Counter:
Tera Steel mandibuzz
Mandibuzz @ Heavy-Duty Boots (rocky helmet guarantees you cannot get outplayed. But rocks cannot be up)
Level: 100
Impish Nature
Tera Type: Steel
Ability: Overcoat
EVs: 248 HP / 244 Def / 16 Spe
- Knock Off
- Foul Play
- Iron Defense
- Roost
OK, This is going to be very confusing. Mandibuzz can easily beat any roaring moon set that because if they run Taunt they have to give up EQ. without taunt. Threatening it to attack in case of foul play, while threateninhg defense boosts if they dont taunt
Make sure to swap in on first turn.
if roaring moon doesnt dd on switchin, the max amount it can do is tera tera flying,
252 Atk Protosynthesis Tera Flying Roaring Moon Acrobatics (110 BP) vs. 248 HP / 244+ Def Mandibuzz: 172-204 (40.6 - 48.2%) -- guaranteed 3HKO
you can iron defense, and you will always live a 2 more hits, meaning you can roost up
252 Atk Protosynthesis Tera Flying Roaring Moon Acrobatics (110 BP) vs. +2 248 HP / 244+ Def Mandibuzz: 87-103 (20.5 - 24.3%) -- guaranteed 5HKO
once you get +2 def, you just press foul play and roost and win.
But what if they taunt you on the iron defense?
If they do that they have no EQ, so Tera steel.
after tera steel, knock off be the max dmg
you can live the initial hit, then roost and live all the sequential hits
First hit:252 Atk Protosynthesis Tera Flying Roaring Moon Knock Off (97.5 BP) vs. 248 HP / 244+ Def Tera Steel Mandibuzz: 153-180 (36.1 - 42.5%) -- guaranteed 3HKO
No Item:252 Atk Protosynthesis Tera Flying Roaring Moon Knock Off vs. 248 HP / 244+ Def Tera Steel Mandibuzz: 102-121 (24.1 - 28.6%) -- 98% chance to 4HKO
K what if they DD on the switch.
immediately tera steel. and hit iron defense.
+1 252 Atk Protosynthesis Tera Flying Roaring Moon Acrobatics (110 BP) vs. 248 HP / 244+ Def Tera Steel Mandibuzz: 129-152 (30.4 - 35.9%) -- 42.5% chance to 3HKO
you live acro, and if they taunt you that means no EQ so without the iron defense boost, just foul play and roost.
+1 252 Atk Tera Steel Mandibuzz Foul Play vs. 0 HP / 0 Def Tera Flying Roaring Moon: 324-382 (92.3 - 108.8%) -- 56.3% chance to OHKO
(same thing happens if they did not tera )
+1 252 Atk Protosynthesis Roaring Moon Acrobatics (110 BP) vs. 248 HP / 244+ Def Tera Steel Mandibuzz: 86-101 (20.3 - 23.8%) -- guaranteed 5HKO
+1 252 Atk Tera Steel Mandibuzz Foul Play vs. 0 HP / 0 Def Roaring Moon: 162-191 (46.1 - 54.4%) -- 55.5% chance to 2HKO
If they have EQ, that means they have no taunt, so you live the maximum dmg+1 tera flying acro and hit an iron defense on the first turn.
+1 252 Atk Protosynthesis Roaring Moon Acrobatics (110 BP) vs. 248 HP / 244+ Def Tera Steel Mandibuzz: 86-101 (20.3 - 23.8%) -- guaranteed 5HKO
then you live a +1 Eq with the +2 defense
+1 252 Atk Protosynthesis Roaring Moon Earthquake vs. +2 248 HP / 244+ Def Tera Steel Mandibuzz: 158-186 (37.3 - 43.9%) -- guaranteed 3HKO
roost up until you can set up another iron defense. foul play 2 rimes ang guarantee win
if they dd more then once, foul play ohkoes
TLDR: Mandibuzz swaps in and can live a hit. since NO roaring moon is going without knock-off, they cant have acro, dd, EQ and taunt. so if they dont have taunt, use ID to set up defense and foul play it, if they dont have eq, just tera steel and foul play.
check:
CB rhyperior

Rhyperior @ Choice Band
Level: 100
Adamant Nature
Ability: Solid Rock
EVs: 252 Atk / 92 SpD / 164 Spe
- Megahorn
- Stone Edge
- Earthquake
- Ice Punch
You live any hit even at +1 and ohko with ice punch. Tera or not
252 Atk Protosynthesis Roaring Moon Earthquake vs. 0 HP / 0 Def Solid Rock Rhyperior: 178-211 (47.9 - 56.8%) -- 89.5% chance to 2HKO
+1 252 Atk Protosynthesis Roaring Moon Earthquake vs. 0 HP / 0 Def Solid Rock Rhyperior: 267-315 (71.9 - 84.9%) -- guaranteed 2HKO
252+ Atk Choice Band Rhyperior Ice Punch vs. 0 HP / 0 Def Roaring Moon: 376-444 (107.1 - 126.4%) -- guaranteed OHKO
252+ Atk Choice Band Rhyperior Ice Punch vs. 0 HP / 0 Def Tera Flying Roaring Moon: 376-444 (107.1 - 126.4%) -- guaranteed OHKO