uncommon cursebound evocation fire oracle 

Mystery flames

Cast [>>] somatic, verbal

Area 10-foot emanation

Duration 1 minute

You surround yourself with a combustible aura. Each time a creature within the emanation takes fire damage, it catches on fire, taking 2d4 persistent fire damage.

Heightened (+2) Increase the persistent damage by 1d4 and the radius of the emanation by 5 feet.

Advanced Player’s Guide, page 232.