Okay, after doing a ton of C&C work for this metagame, I've come to a realization:

is unhealthy.
Why? Everyone is well aware of Geomancy, coverage options to hit everything and its only limitations really are potential limitations of Terastallizing and not having the moveslots to cover everything, but the only two legitimately viable (sorry

pink blob) checks to it are

and

, and basically every single viable team that isn't hyper offense (which in itself has its own issues) requires having at least one of those two to be good, and even then those two can be circumvented, namely

in itself is required to check a good portion of the metagame, and given it has no reliable recovery it's not too difficult to overwhelm long term, and

just dies to anything involving Teras unless it Terastallizes itself, which is just a mind game where

is actively on an advantage, as it can just safely switch to something else over using Geomancy or try to fish for a paralysis with Thunder, Z-Geomancy + Ingrain sets also just invalidate it as a check.
As mentioned before, hyper offense teams do "check" Xerneas, but basically rely on applying offensive pressure to prevent it from using Geomancy without becoming easy to revenge kill by priority, although sets involving Tera Ghost or screens support aren't unheard of.
Actually, I'll go over the rest of so-called counterplay in the provided list
here:
View attachment 607382




: Mostly limited to stall (and are quite niche otherwise), Ferro also doesn't do much back especially against Substitute variants.

: Substitute being up means it's a dead slot, and it can't OHKO Xerneas even after the chip of doing a Substitute, so at best it's a trade where Xerneas actively has the advantage.

: Niche in general, relegated to matchup-fishy Trick Room teams (a subset of offense BTW) and also lacks reliable recovery, Mag itself falls as a soft-check as all it wants to do here is set TR and pivot to a breaker like

,

or

, as Fleur Cannon can't 2HKO after Geomancy, and if you're a mad lad running Heart Swap there's a blatant opportunity cost. There's also the matter of Tera Electric Thunder after Geomancy OHKOing after Stealth Rock, lol.

: Why is this thing here? It's not even ranked on the VR nor tiered as Uber, Bullet Punch may seem intuitive, but Tera Electric flips the match-up and it's just the one being KOed instead.

: Limited to act as a revenge killer as +2 Moonblast after Stealth Rock just OHKOes (with it being a roll otherwise), and even then Extreme Speed can only 2HKO with some chip after Tera Normal, so in the best case scenario

left a mark on your team if you have to rely on the llama to finish it off, and that's ignoring Substitute preventing the llama from properly nuking the deer if it's up.

: This is quite an opportunity cost as an Arceus forme as it loses to a ton of top threats like

,

,

,

,

and

, if it wasn't for

I'd rather just use

, which speaks by itself.

: As it does not invest on bulk at all, Xerneas can overwhelm it even more easily than

, as +2 Tera Electric Thunder just OHKOs even without entry hazards. With Intrepid Sword intact, Play Rough can OHKO Xerneas after Stealth Rock (otherwise being a very low roll), but given the above it's not a consistent answer beyond offense teams when it can just keep applying offensive pressure alongside the rest of its team.

: Good option on paper but given the raise of Tera Electric

, it's way more of a soft check these days, and +2 Tera Electric Thunder just OHKOes unless it's specially defensive, which does quite little besides checking

and maybe :mega mewtwo y:.
Notice a pattern? Xerneas is mainly held back by the accuracy of Thunder to circumvent most of its counterplay, which in itself isn't competitive as the match is decided a good amount of the time on if it hits, with that being actively on Xerneas's favor, and the above is ignoring that Xerneas has teammates to circumvent the stuff that at this point is "meant" to lose to, this is one of those mons that can pick its counterplay and not in a good way.
I may as well do comments on the other stuff in the survey:

: With

gone it's no longer forced to run Tera Fairy, and it sure benefits from that, between acting as a physical

with the obscene bulk when you think you're about to KO it, let alone having a surprisingly good movepool to complement the fact it only needs one offensive move as it hits the entire meta but Terastallized Grass-types at least neutrally, it's a quite strong mon, but what arguably breaks it in particular alongside those traits is Glare, as it can cripple anything whatsoever, with the only real immunities (Electric-types) being weak to its own STAB move, and so it can try to fish for multiple paralysis-forced passivity turns to break past some of its checks, or act as a wincon itself with Coil or Dragon Dance.
I wouldn't oppose some tiering action to this mon as you can no longer consistently force it out with Ice coverage.
View attachment 607381: Teras have definitely rendered a good chunk of stuff that'd otherwise be fine into a thin line at best, however, Teras were already suspected and deemed fine to stay, and I don't think the Stellar-type has really changed that status quo, with the main abuser of that being

either way.
The
Ubers tiering policy does favor complex bans over doing "collateral damage", so there's also a possibility the Pokemon above are complex banned as being unable to Terastallize, but I don't think everyone would be comfortable with that these days.
This is a great post and I agree with most of what you've written. Also thank you for your work in C&C. I'm really looking forward to having fleshed out strategy dex pages for the tier and that wouldn't be possible without the time and effort put in by yourself and others.
Why? Everyone is well aware of Geomancy, coverage options to hit everything and its only limitations really are potential limitations of Terastallizing and not having the moveslots to cover everything, but the only two legitimately viable (sorry

pink blob) checks to it are

and

, and basically every single viable team that isn't hyper offense (which in itself has its own issues) requires having at least one of those two to be good, and even then those two can be circumvented, namely

in itself is required to check a good portion of the metagame, and given it has no reliable recovery it's not too difficult to overwhelm long term, and

just dies to anything involving Teras unless it Terastallizes itself, which is just a mind game where

is actively on an advantage, as it can just safely switch to something else over using Geomancy or try to fish for a paralysis with Thunder, Z-Geomancy + Ingrain sets also just invalidate it as a check.
I wrote a fair bit about

the other week and at times will probably pull some stuff from those posts which can be found in the previous page of this thread. Where we disagree is that I believe

is truly the only good

check. Ingrain certainly does invalidate it and
R8 is a big fan, but at least presently, it is not common and does come with an opportunity cost in the form of valuable coverage.

does live any attack and can phase it. +2 Moonblast maxes at 85% which does give

a bit of wiggleroom at least. The tera mindgames as you say certainly do come into play, though that speaks to bigger issues with tera itself. I agree that the

user is at an advantage as they are rarely obgligated to geomancy and can just chuck out an attack and set up later, something a lot of

users are surprisingly reluctant to do.
HP Rock Focus Blast is the best

set in my opinion. HP Rock is a coinflip to OHKO

from full and is guarenteeed easily by something as simple as toxicing it. It is also not tera reliant, particularly in comparison to
/
. It only needs to tera in specific matchups such as

. This flexibility allows it slot into a lot more teams. For example it is a fantastic partner for

. It also entirely invalidates even defensive

entirely as a check should it chose to tera as
focus blast is a 68.8% chance to OHKO and is guarenteed with rocks up even if

is taking 6.25% on switchin.
On that note,

is a defensive check by the flimsiest of margins.
In Smog 32 a check is defined as " Pokémon A
checks Pokémon B if, when Pokémon A is given a
free switch into Pokémon B, Pokémon A can win every time, even under the worst case scenario, without factoring in hax." Defensive

can only consistently do this if it runs roar. Though this is a viable option, it is hard to fit for most teams and requires giving up a generally more useful move. Offensive

does revenge it, but requires chip since blades tops out at 74% and heat crash does not OHKO even from 252+.
Defensive

only wins the 1v1 under certain conditions with those being

is
/
, has already tera'd, and is not behind a sub. If all three of those conditions have not been met

loses. Since

cleanly (well 99.6% of the time) 2hkos

with +2 moonblast,

must be able to OHKO back. It doesn't do this even if

has had its sub broken and taken rocks chip.
So to actually answer

:
a) Can't freely switch in
b) Essentially requires

to have and use
/
c) Still has to actually hit precipice blades
d) Requires

to be heavily chipped if it hasn't
/
e) Has to be fairly healthy in the first place
You touch on the last point in your post and it is perhaps the most important. If you arn't running HO,

is not likely to be in great condition by the time

comes out due to needing to do

things such as setting hazards and answering other mons. Sure one can invest beyond the baseline of 204 SpD, but that comes with its own issues such as being OHKO'd by +1

EQ and being 2HKO'd by


.

is a good

check if it is not running
and I'd argue is generally a better one than

.


is a good set and does invalidate

but it comes with lots of drawbacks and isn't something that moves the needle for me. The inability to tera, lack of coverage, and the free turn it provides to switch to counterplay prevent it rising to the unhealthy level of standard geomancy sets even if it can frequently end the game on the spot.
Actually, I'll go over the rest of so-called counterplay in the provided list
here:
This hasn't been updated since April when the tier was in its infancy and I would not be surprised if it was largely copy and pasted from previous generations of ubers with new mons added. As you ask in your post, why is

here? I can't think of another reason why it would be.

checking it is questionable in the first place. As you've mentioned, it struggles immensely with substitute, but more importantly it doesn't really do anything to

other maybe annoy it slightly or leech it and switch to teammate which can actually handle it. Most

sets either run focus blast and / or a tera which resists gyro ball and this was the case even in April. On another note, gyro ball is as close to an unviable move on

that still has some justification for being used and that is being generous.

struggles fit moves beyond its standard four and knock off or thunder wave are far more useful than gyro ball.

is legitmately probably the best

answer we have (I'm not going to pretend psyshock

is real). The problem is, well, it is

. You can count on a single hand the number of teams it fits on.

: Substitute being up means it's a dead slot, and it can't OHKO Xerneas even after the chip of doing a Substitute, so at best it's a trade where Xerneas actively has the advantage.
Agreed. Though it works a bit better in game. It does revenge

if it has taken any chip or hazard damage before subbing. If

is your counterplay you are saccing something to allow it to come in and that should generally mean you can prevent it from having a sub up and being out of

range in the process.

: Niche in general, relegated to matchup-fishy Trick Room teams (a subset of offense BTW) and also lacks reliable recovery, Mag itself falls as a soft-check as all it wants to do here is set TR and pivot to a breaker like

,

or

, as Fleur Cannon can't 2HKO after Geomancy, and if you're a mad lad running Heart Swap there's a blatant opportunity cost. There's also the matter of Tera Electric Thunder after Geomancy OHKOing after Stealth Rock, lol.
Maybe I'm out of date, but answering

is a massive portion of why

is even viable in the first place. It compresses a

and

check for fat balance builds which is a valuable niche. It is dogshit outside of that role, but that compression is invaluable for those types of squads. It is pretty far down the list of TR setters and really its selling point is its


matchup which otherwise destroys most TR teams.

: Limited to act as a revenge killer as +2 Moonblast after Stealth Rock just OHKOes (with it being a roll otherwise), and even then Extreme Speed can only 2HKO with some chip after Tera Normal, so in the best case scenario

left a mark on your team if you have to rely on the llama to finish it off, and that's ignoring Substitute preventing the llama from properly nuking the deer if it's up.
True, but

is most a HO mon anyways which is likely going to leave :xerneas in espeed range as it sets up anyways. It is surprising to not see

on the list as the interaction is similar, ableit from a lower in in exchange for not thudding into
.

: As it does not invest on bulk at all, Xerneas can overwhelm it even more easily than

, as +2 Tera Electric Thunder just OHKOs even without entry hazards. With Intrepid Sword intact, Play Rough can OHKO Xerneas after Stealth Rock (otherwise being a very low roll), but given the above it's not a consistent answer beyond offense teams when it can just keep applying offensive pressure alongside the rest of its team.
If

is
it usually runs thunderbolt as the main appeal is
thunderbolt not needing to risk that 30% miss to OHKO

.
Thunderbolt is a 25% chance to OHKO but it becomes a guessing game as moonblast wont and
is immune while
CC or play rough both KO with very little chip. It isn't a consistent answer, but is good enough be considered a soft offensive check imo.

: Good option on paper but given the raise of Tera Electric

, it's way more of a soft check these days, and +2 Tera Electric Thunder just OHKOes unless it's specially defensive, which does quite little besides checking

and maybe :mega mewtwo y:.
Yeah defensive

is mid as hell and is a

/

check that can't beat

/

due to having immense difficulty in fitting EQ. Both DD sets,

and defensive, do a decent job checking it. IMO, most teams these days that run defensive

can replace it with defensive DD (same evs but 36 speed) and would be improved. It actually checks the things that

is supposed to for the most part and can will ocassionally sweep. I.e. it uses

as setup fodder as it will likely eventually miss a fire blast and that lets it get a 2nd DD.
Notice a pattern? Xerneas is mainly held back by the accuracy of Thunder to circumvent most of its counterplay, which in itself isn't competitive as the match is decided a good amount of the time on if it hits, with that being actively on Xerneas's favor, and the above is ignoring that Xerneas has teammates to circumvent the stuff that at this point is "meant" to lose to, this is one of those mons that can pick its counterplay and not in a good way.
I somewhat agree though I'd replace thunder with focus blast.

is

taken to a new level. The most pressing issue

has is how the two flex slots it has matches up into your team.

can't blow past every team with those two slots, but it sure as hell will blow past most of them. This is what makes it so hard to answer defensively. You have
/

that lives any hit full and can phase, but even that depends on

not having ingrain and actually using geomancy. Plus you still have 5 other mons to deal with. Building a varied '

proof' that is actually good is near if not impossible barring maybe a couple of stalls. You can't reasonably answer all of HP rock, sub, ingrain, focus blast, thunderbolt, and some other move i'm forgetting
. This also ignores other rare, but viable options such as draining kiss, aromatherapy and tera
.

: With

gone it's no longer forced to run Tera Fairy, and it sure benefits from that, between acting as a physical

with the obscene bulk when you think you're about to KO it, let alone having a surprisingly good movepool to complement the fact it only needs one offensive move as it hits the entire meta but Terastallized Grass-types at least neutrally, it's a quite strong mon, but what arguably breaks it in particular alongside those traits is Glare, as it can cripple anything whatsoever, with the only real immunities (Electric-types) being weak to its own STAB move, and so it can try to fish for multiple paralysis-forced passivity turns to break past some of its checks, or act as a wincon itself with Coil or Dragon Dance.
I wouldn't oppose some tiering action to this mon as you can no longer consistently force it out with Ice coverage.
I don't think

is banworthy even in a tera meta. I'd be fine with a suspect though I'd likely opt not to ban it. A mon of

's caliber in any tier requires prep in the teambuilder and every style of team has a plethora of options at their disposal for doing so without compromising matchups into other threats. Occasionally

will win matchups it really has no business winning via obscene para hax, but this is not something that happens with near enough consistency to cross the threshold of banworthy for me.
Stall blanks it entirely though a perfectly played dragon tail

can a slight headache. Most often it is just absorbing status and weak hits while its teammates handle the breaking. Balance/BO can run mons such as Taunt

, CM

,

,

,

,

(works best as a pivot
loses in the long run) among others. There is a good chance that balance and BO squads are already running these mons or considered them for other reasons even if they didn't make the final team for other reasons.

is also a bit of a tera hog. This isn't a major issue for it due to how effectively it leverages tera, but it often requires tera to reach its full potential. This can be a bit of an issue when other mons need to tera to check threats such as

to phase

.
Frustratingly often I'll see people complain about

being banworthy and after showing their team there is a singular mon that checks

when healthy such as

or offensive

that lose the ability to do so when paralyzed. They'll moan about how

just stayed in and
/
and glared it and then they lose since

walls the rest of the team. It is always

is broken and never any introspection about what could be changed with the team to address the

matchup with this crowd.
Unrelated and 100% not suspectworthy,

is a significantly larger headache to play against than

.
: Teras have definitely rendered a good chunk of stuff that'd otherwise be fine into a thin line at best, however, Teras were already suspected and deemed fine to stay, and I don't think the Stellar-type has really changed that status quo, with the main abuser of that being

either way.
The
Ubers tiering policy does favor complex bans over doing "collateral damage", so there's also a possibility the Pokemon above are complex banned as being unable to Terastallize, but I don't think everyone would be comfortable with that these days.
I agree that stellar has not in anyway moved the needle with tera.

and

sometimes run it and that is about it. While a complex ban surrounding tera may fall in line with policy it is something I am staunchly opposed even if the options are between keeping tera and a complex ban. I've come around to liking tera a lot more since the suspect and am open to the possibility that it may be balanced enough to keep around if

leaves but that is a conversation to be had when or if the time comes.

is the only other mon that makes me go fuck this mechanic it needs to go. Everything else feels 'honest' enough to keep tera around (if the primals could still tera I'd 100% want it gone) even if I think the tier would likely be more competitive without it. The tera should be present in the tier or it shouldn't and the middleground of a tera list a la SS Ubers dynamax is the wrong way to go. For what its worth, I do not want

unbanned if tera is axed.