Jellicent @ Mental Herb / Sitrus Berry / Kasib Berry / Colbur Berry
Ability: Water Absorb
EVs: 244 HP / 132 Def / 132 SpD
Relaxed Nature
IVs: 0 Atk / 0 Spe
- Scald / Water Spout
- Shadow Ball / Will-O-Wisp
- Trick Room
- Recover / Will-O-Wisp / Protect

252+ Atk Guts Hariyama Knock Off (97.5 BP) vs. 244 HP / 132+ Def Jellicent: 340-400 (84.5 - 99.5%) -- guaranteed 2HKO
Use the type resist berries if you need to live Z moves from Hydreigon/Gengar