Slowbro-Mega @ Slowbronite
Ability: Regenerator
EVs: 252 HP / 76 Def / 180 SpD
Bold Nature
IVs: 0 Atk
- Scald
- Slack Off
- Calm Mind
- Psyshock
Silvally-Steel @ Steel Memory
Ability: RKS System
EVs: 252 HP / 240 SpD / 16 Spe
Calm Nature
IVs: 0 Atk
- Parting Shot
- Toxic
- Flamethrower
- Defog
This team has no haze, phasing moves, or toxic, making it very weak to fat set up. Silvally-Steel serves as a solid switch-in to Pokemon that Slowbro cannot deal with before any boosts, like Rotom, Nihilego, and Latias; it can also defog away Nihilego's toxic spikes. Parting shot weakens the attacks of whatever you use it on, while also giving Slowbro a free switch-in, making it easier to set up.
Slowbro itself is very difficult for this team to stop after just one cm boost. For example, if Rotom switches in on Slowbro as you click cm, then leaf storms before you click cm again, it cannot KO you with a second leaf storm:
252 SpA Rotom-Mow Leaf Storm vs. +1 252 HP / 180 SpD Slowbro-Mega: 240-284 (60.9 - 72%) -- guaranteed 2HKO
-2 252 SpA Rotom-Mow Leaf Storm vs. +2 252 HP / 180 SpD Slowbro-Mega: 90-108 (22.8 - 27.4%) -- 46.3% chance to 4HKO