In 0.75, which will be out before the end of the month- you'll enter a dungeon called the "Ignis Volcano"
As it's name suggests, it's a very... firely place. Wild slugma, torkoak and magmars can be battled here.
In addition to that, you'll fight the first Corrupted Legendary
Pokemon: Moltres. But unlike normal corrupted Pokemon, you will not be
able to use legendaries on your team.
Instead you summon them into battle to deal massive damage (Final Fantasy style!)