Bound Spirit: Balor

Twice per long rest, as an action, you can split your bound fiend spirit from your main body to summon your inner Balor. It appears in a space you choose within 90 feet, and rolls its own initiative. You control it mentally (no action). You can speak from it as well. You can dismiss it as an action or bonus action on your turn, or on its turn.

It has one hit point pool of 262 hit points. So, if you summon it in the morning and it takes 100 damage before you dismiss it, then if you summon it again at night before you long rest it will have 162 hit points when summoned.

When you long rest, it long rests. If the Balor is ever killed, you cannot summon it again for 2 weeks.