Heir of Fire

Your destiny to become one with flame has already begun to manifest itself in a few ways, granting you the following features:

• You are resistant to fire damage unless bound in iron (shackles, manacles, etc.). 
• When you cast a spell that could potentially deal fire damage, roll a d20. On a 1-4, the spell bursts out in an uncontrolled spew of fire that misses the intended target/area. On a 18-20, your innate fire magic up-casts the spell by one level without using a higher spell slot (if applicable, the original spell slot is still used.)
• At the DM's time of choosing, when you or someone/something you are emotionally attached to is severely injured, you grow fae-like features for the next 1d10 minutes and must make a Wisdom saving throw, using your own Spell Save DC. Upon failure, you and any hostile presences of your choosing within 20 feet take 8d8 fire damage as fire violently explodes from your being. Any object not being worn or carried within the radius becomes incinerated.