>>41856742Make the games Let's Go Pikachu Gold and Let's Go Pikachu Silver.
Pikachu is still the partner, but now can have a "cheerleader" that can be any of Chikorita, Cyndaquil, Totodile, Pichu, Cleffa, Igglybuff, Togepi, Bellossom, Jumpluff, Wobbuffet or Delibird. As long as the cheerleader is in your party and healthy, they will pop out of their ball whenever partner Pikachu fights, giving it special boosts.
Pikachu is always your party leader, you cannot change its placement.
If Pikachu is about to be knocked out another pokemon jumps in and takes the hit instead. This ensures Pikachu will be your last pokemon, though due to bad forethought it can still be defeated prematurely by passive damage, letting you fight with other pokemon.