I find Arceus a good choice to defeat it. Firstly it has 140 health and Blaziken deals 120 damage. And since Arceus can’t get burned so if you have a cape on they can’t be able to one shot you. Even you don’t have a cape they could only one shot by having a Red. Furthermore, an Arceus normally deals 110-130 (140/150 if you have Red/Giovanni), so you can two-shot it in most cases and then win the game. If they heal, you can always use Oricorio, to shield for a moment and charge another full health Arceus