Gen 7 Double Battle Support
The Pikachu of Mercy (Pikachu) @ Focus Sash
EVs: 128 Def / 128 SpD / 252 Spe
Relaxed Nature (Sacrifices Speed for Defense, helping it live a bit longer)
- Surf: Handles Ground-types, plus helps allies with abilities like Water Absorb, Storm Drain, and Dry Skin.
- Discharge: STAB, plus damage other Pokemon plus helps allies with abilities like Lightning Rod, Motor Drive, and Volt Absorb.
- Volt Tackle: STAB, plus paralysis. Needed for Catastropika (Ya gotta defend yourself in some way)
- Grass Knot: In case of heavy Ground-types or Water/Ground types, plus helps allies with abilities like Sap Sipper. (If you aim at the ally that is!)
This can be used in a way like how most people use Smeargle, A stat boosting or HP helper. Just this time using attacking moves. Think of it like the attacking-but-helping Smeargle.
To get a Pikachu with Surf, transfer the Pikachu in Pokemon Yellow or if playing in USUM, become champion in all the surfing spots.