Dance in Flames

Once per battle when an enemy moves to engage you, you can roll
a normal save (11+) as an interrupt action.
deal 5 ongoing fire damage (5th level: 10 ongoing; 8th level: 15 ongoing ).
Adventurer Feat: You can use it twice per battle.
Champion Feat: you can use it at-will, though it still requires an
interrupt action (and is therefore likely to apply only once
per round).
Epic Feat: Once per battle, you can use it as a free action