252+ SpA Mega Charizard Y Overheat vs. 252 HP / 252+ SpD Assault Vest Regice in Sun: 122-146 (65.2 - 78%) -- guaranteed 2HKO
Wow! Why do noone ever uses regice?
Well I used this(is that why you brought it up .:)
AV Regice is good in a lot of ways, but no recovery(even non-AV only has Rest,) 4 weaknesses with just one resist, slightly lacking power, and low Spe all hurt its viability a lot.
Im not sure if AV is the best item. It was the one i was immediately drawn to tho. Specs is too limiting imo, and bulkier sets like Sitrus and such are offset by the fact that so many strong physical things 2hko or better anyways and theres no other recovery or good way to miyigate damage like WoW or Reflect(Ive thot about Amnesia, but youd want Iron Defense, and Regice doesnt have that. Boostint the SpD more would be great if they had no physical attackers, but is still super susceptible to Toxic, WoW, and CM users.)
A different ev spread than what you used in that calc is best. Zard Y 2hkos with Fire Blast even when youre max special bulk, and Flamethrower does fine too. The spread I made was like 252 HP/ 92 Def/ 160 SpA(HP Grass)/ 4 Spe. That gives a bery good chance to live regular Chomp's Stone Edge, and always lives Max Atk Kang's DE to smack it with Focus Miss...mayb. Still loses tho, and Rock Slide and stuff exists, but you wouldnt wanna drop bulk much if at all cuz Mence.
The moveset I used was Ice Beam/ Charge Beam/ Focus Blast/ HP Grass(in-game ine is completely flawless Calm, except 30 SpA. Kinda a shame not to use HP Grass to make use if that blemish, and its not bad besides.)
Charge Beam over t-bolt since the boosts help a lot. Charge Beam makes for a good finisher when foe is low health(better than Ancientpower, which i changed for HP Grass,) amd the situations where you'd use t-boot are fairly few, so imo the power is not missed.
HP Grass is the only other move explanation might be neccesary. It's the best move against Rotom-W by a little, power of Focus Miss without the accuracy. Hits water/ grounds hard which is a nice surprise against Swampert in particular, though I remwmber it doesn't kill. Lets you beat out Gastrodon and Quagsire though. Also best move vs the odd Lanturn. Tiny bit better vs water types not weak to fighting or neutral to ice since Charge Beam has slightly less BP and can miss. Often though it's better to use Charge Beam or switch.
Another thing for HP Grass is that the move i was using at first, Ancientpower, mainly targets Zard Y, Talon, and Volcarona.
Zard Y only dies to Ancientpower Regice with SR on the field, and that can be hard to manage. Talon can kill Regice easy with Flare Blitz, and do the same with Brave Bird with some prior damage. Again it's not that helpful, unless maybe if you have Reflect or something to take w/e hit and ohko back. Volcarona really does lose to Ancientpower most of the time, but it's the least common target of it that's still pretty relevant, and with proper boosts it wins just fine. Ofc, Refice may have boosts of its own so yea.
Anyways, Regice overall is pretty meh. Not god awful at all, but tricky to utilize effectively. If you can do good with it(65% GXE mayb?) that's worth just about any number of wins with a team thats S tier and w/e, but good luck witth doing really good with it.
I've thought about what else mught be good for Regice, but most stuff seems questionable at best. Regice gas Curse, Ice Punch, orher physical coverage, and ofc Rest. That and a huge SpD make a Curse set wirh a Chesto Berry seem good, but you're using a base 50 atk stat, which is pretty crumby. A Gravity setter might be ok, since it has stuff like Focus Blast, Blizzard, and Zap Cannon. Gravity doesn't last long though, and Regice is definitely too slow to make proper use of an Eject Button.
Being a t-wave or Toxic spreader isn't bad, but it's nothing new, so there are better things for it. A Rock Polish and Weakness Policy set might be fun, but isn't absurdly fast even if you manage to set up, weak to priority, and les bulky than normal. There isn't really much else. Regice likes the rain, but there are better setters. Icy Wind is a good move, but gives up too much power to lower Spe one stage.
