Sigil of the phoenix

You are Marked with the phoenix, allowing you to burn those around you. You gain the following benefits:

• you gain the ability Phoenix's fury. you may use the ability as an action or reaction if your health falls below 10% from an attack and it lasts for one minute. once you use the ability you must roll a d4 during each long rest, on a 4 you regain the ability.
• once you activate Phoenix's fury you deal 5d6 fire damage to everyone within 5 feet of you and you regain hit points equal to the damage dealt.
• While Phoenix's fury is active you gain; When you deal fire damage add an additional d10 to the damage.