>>471823511. Snap photo of ho-oh, which can appear either right at the start by the charmander or above the big round room with the two charmanders and the graveler
2. Pop all three feathers with an orb - one's by the round room, the other's hiding under a torkoal in the blue magma room, and the third is by the big pillar at center of the blue magma room
You don't need to interact with typhlosion at all