The vast majority of high-ladder and tournament players don't find Roaring Moon broken anymore.
I really doubt Iron Moth would be broken with Koko around. Even right now, there are often times when it thuds into some match-ups 'cause it didn't get the Fiery Dance Special Attack boost. Allowing it to run HDB would make it a bit more consistent, but it'd mainly be the Specs set that is more effective with Koko around, and you still need to predict well to really make it work. I'll give that Iron Valiant might be unhealthy if it can get the Quark Drive boost multiple times, but other Paradoxes also get that same advantage, allowing them to revenge kill/force out Valiant or force out Valiant by coming out on the same turn as it. I give that Tapu Koko would be better in SV OU than it is in NatDex since NatDex has more fat Grass-type options (Ferrothorn in particular) as well Megas Latias and Latios, but I'm not convinced it will tear OU apart given we have stuff like Ting-Lu (eats Tera Ice Tera Blast), Slowking-Galar, Iron Crown, Garganacl, Clodsire (eats Tera Ice Tera Blast), and Iron Treads as well niche options like Fezandipiti and Venusaur in Sun. Regieleki without Tera Blast would also be meh and probably wouldn't even be OU, much like in Gen 8.
Yeah, Raging Bolt would be a big beneficiary of Electric Seed if one were to opt to use that set, but that set still gets walled by specially bulky Ground-type Pokemon since it won't have the power to break stuff like Clodsire and Ting-Lu while pure Electric as a Tera Type would be lackluster for it since it keeps the Ground weakness while not gaining much in returning aside from shaving off the Dragon and Fairy weaknesses and losing the Dragon typing's useful defensive profile. While I can see some more than niche use for Hoopa-Unbound with Electric Seed since it'd make it harder to revenge kill, I believe Hoopa-U would prefer something that provides more consistent value since Electric Seed is only a one-time boost. Dondozo actually beats Tera Electric Tera Blast Hawlucha in Electric Terrain without popping Tera itself and can Curse up on it given Hawlucha's 92 Base Attack.
252+ Atk Tera Electric Hawlucha Tera Blast (80 BP) vs. 252 HP / 252+ Def Dondozo in Electric Terrain: 194-230 (38.4 - 45.6%) -- guaranteed 3HKO
I see your point that Koko being around would increase the volatility of the tier given the number of threats it enables, but I'm not convinced that there would be more than one ban (Iron Valiant if even) from its presence.
This is a lot to cover. We can agree to disagree on a lot of threats. But I do think the scope of what E-terrain impacts would be quite wide. I also have an opinion on Roaring Moon, but I won't get too into that as to not further clog the thread. As for some other points, I'll briefly go over a few.
Iron Moth could potentially be used on a hybrid Sun team. The combination Quark Drive + Specs (or even LO) + Sun Boosted Fire moves would have insane breaking power. A bit specific, but I do think that specific set would be broken. Moth on more regular e-terrain teams is more debatable, but still probably very strong. It's already solidly A rank.
I'm also wary of Iron Boulder because its biggest problem is power. And you can't sacrifice BE speed for power or it also loses its potential niche. But this goes away with E-terrain, allowing you to use a damage booster item. It has a STAB move that goes through protect.
It is likely TB could break several of the E-terrain mons, potentially including Koko itself. Regieleki was brought up because it would be an alternative of if TB is banned. Slight oversimplification coming, but all you would have to do is build a team that destroys Ground types (and maybe Ring Target shenanigans) and you would be cooking with triple damage multiplier Electric moves at 200 base speed. Yeah, I could see that being an issue.
Raging Bolt with E-seed would like run Body Press for Ting-Lu. I ran a Tera Fighting BP set on Grassy Terrain and it was filthy.
I made a mistake with Dozo not factoring out the SD cancelation. That is my bad. Hawlucha would still tear through teams that can't fit Dozo, by my estimation.
Wait
Wait, I thought Levitate cancelled out the terrain bonuses. Outside of the seed consumption.
You are correct. I was focused on the E-seed activation and forgot the extra Thunderbolt damage would not proc for Levitate mons. This was my mistake. Tera Electric could still work defensively, but carrying Thunderbolt wouldn't be any better.
What viable options does National Dex have (other than Ferrothorn) to deal with Koko that OU does not also?
Mega Swampert, Charizard X, Mega Lati twins, Mega Venusaur, Archaludon, and Volcarona. Alolan Marowak is also a thing, though that is RU.
Anyway, something else extremely important to Koko's viability is HP Ice. Boots Koko without HP Ice can't immediately threaten Lando-T, can't make any meaningful progress against Gliscor, and also has to run U-Turn over Volt Switch. I don't think Specs Koko would be as threatening as it used to be without HP Ice either. Bro has 95 base spatk, it really needs that terrain electric STAB or supereffective hits to do much damage.
Tera Blast Ice is stronger? Lando-T also gets warn down over time, so you can chip it with a non-Electric move and/or pivot off it with U-turn if you don't have immediate KO. Gliscor would be a bigger issue without Ice coverage because it has sustain. So I'm not even sure why T was the example here.
You are also assuming a special set, which is not necesarrily a safe assumption even though Wild Charge has a lot of drawback.
I guarantee Electro Ball will be terrible. In general, people underestimate just how much faster you have to be than your target for Electro Ball to substantially outdamage Tbolt. I also guarantee Agility would be terrible. Koko has negative immediate power and Agility has literally never been good except for double dance cheese and extremely unique cases such as Magearna (who has Soul Heart).
I do think Mixed Sets might exist for Gking but Koko really doesn't have enough expendable EVs to be a threatening mixed attacker, especially since Z-Moves don't exist here.
D-speed can use a mixed attacking set despite having only base 95 in both attacking stats. Why? Because, aside from its coverage and high BP moves, it doesn't need to invest in speed. It can save most of its EVs for both attacking stats. Koko could potentially do just this if it had Agility. You can also run a damage boosting item to get more power.
It couldn't do this if it was looking to use Electroball, though, because it wouldn't have speed to spare. So it would have an awkward split of EVs. I'm not entirely sure myself if Electroball would be good, so I'll leave it at this. Maybe it's a stretch.
And even if all of these sets were used, this wouldn't necessarily make Koko banworthy. Like none of this really changes Koko's counterplay at all.
Says the one who just admitted people could run mixed sets for Glowking. I just don't believe this line. There are too many one sides walls to exploit.
Agree, but no one ever said Zama is the Koko counter. It's just an example of something Koko doesn't beat as easily as it should.
So what? My initial point was about Koko's speed tier. Also, how the unboosted 3 mons that are faster aren't all as good into it as you might want. Zama not stopping Koko means you can take advantage of its speed against more teams. That's a pretty big difference.
Don't think the Tera Blast arguments work at this point. Could be said about literally any offensive threat ever.
The point is complimentary STAB coverage. Bolt/Beam is a thing, you know. Earlier, you made a paragraph on how Koko needed HP Ice. But Tera Ice is more powerful and fills a similar role. Mons like Iron Valiant can get TB, too. Both Ghost/Fighting and Dark/Fairy are great STAB combinations and Valiant can get both with TB. But on E-terrain, it becomes even better when it doesn't have to choose between speed and power.
Yes, it can be applied to every mon. But not every mon abuses it equally well. E-terrain introduces a whole new set of factors to consider with TB.
Life orb is not an item that exists and for good reason.
You sound like someone who never played mixed attacking D-speed. LO Dragonite is also a thing. If you have the hazard support, or really just removing rocks, you only need 1 DD to do damage you'd normally need 2 for. LO is a good item for certain case. Mixed attackers will often want LO, too.
Swagger/Mirror Herb is just reaching at this point and you know it. People usually just list every possible combination of moves/items they can think of when trying to make a mon sound as broken as possible.
The point was set variety and this is a thing Koko could run. Is it niche? Yes. But it is a way to boost the attack while confusing a wall such as Glowking.
It's not that easy to say 'then don't run boots.' As you said earlier, this is a hazard spam metagame... None of our hazard removal has even passable longevity imo (tusk is worn down way too quickly, it just makes up for it by being a massive threat).
First of all, Treads is likely the e-terrain spin mon. Not Tusk. Second, I disagree with boots spam on a fundamental level and build all my teams accordingly. Third, the anti-hazard options this gen are actually pretty good. You can almost guarantee hazard don't stick in most games by having a primary remover and a secondary option. Or you can use niche options like Geezing. You can also build teams to counter some of the hazard leads and/or be less hazard weak in the first place.
If I don't want to run boots on Koko, I won't. And especially if you aren't a full E-terrain abusing team, you could have one or two mons that take advantage of it and not necesarrily need to switch in Koko so many times per game.
Screens Koko would be a set but then you're picking between clay and terrain extender.
First world problems. This is still enough to set up with a Quark Drive mon. Or Hawlucha. Or Bolt. Depending on what you are doing, Light Clay might be better if you were activating E-seed. If not, Terrain Extender might be better. Either way, it's good.
Seriously give me an example that's not gking switching in on wild charge. Not only that, band is very likely completely unviable.
Blissey switches in on a Wild Charge. Or Zama switches in on a Tera Flying Brave Bird. Ting-Lu switches in on TB Ice and gets 2HKO'd? Gliscor gets 1HKO'd. I also don't think CB is unviable in a tier without Ferrothorn to severely punish Koko's recoil moves.
Finally, there's no way Koko gets Toxic or Defog. Even if it got Defog, that wouldn't make it broken but rather more healthy lol.
While this is likely, we don't know for sure. T-wave and Taunt could still be decent support, especially if you have a Hex abuser. I do agree that Defog would be healthy, but it would also add to set variety.