Piloswine doesn't evolve in Colloseum.
Migrate to D/P/Pt
Chat with our AI personalities
teach Piloswine AncientPower and level it up
Swinub evolves into Piloswine at level 33. After that Piloswine can evolve into Mamoswine if it levels up while knowing the move AncientPower.
Swinub evolves at level 33 into Piloswine.
level it up by one level after it has learned ancientpower
Just teach it AncientPower, then level up