The title might've been a bit confusing, so I'll explain. In Doubles, you are able to make a Pokemon "stronger" by attacking it with your other Pokemon, like this: Tapu Koko uses Discharge with a Mega Sceptile as its ally. Discharge will activate Lightning Rod and raise Sceptile's Sp. A. I'm not counting like using moves yourself to raise stats, I mean to raise stats while attacking. This also contains Z or Max/G-max Moves!
Clangorous Soulblaze inflicts damage to all opposing Pokémon and increases the user's Attack, Defense, Special Attack, Special Defense, and Speed stats by one stage each.
Source Source 2
Moves:
Contrary makes moves that lower user's stats raise them instead. Simple doubles stat changes
Max moves
If I missed any, let me know. Thanks