Verratrix’s Blood Crystal

You undergo a ceremony in which you spill your own blood into a chalice, then imbue it, transforming it into blood crystals, palm-sized crimson gems which have one-time uses. During the casting of this spell, reduce your maximum hit points by a number of d8’s equal to the level this spell is cast. Your maximum HP can only be restored via a wish spell, or when you finish a long rest. In turn, you create a number of blood crystals equal to the level this spell is cast. You can benefit from the crystal yourself or give it to another creature. As a bonus action, you can crush the crystal in your hand, expending it, and choose one of the following effects:

- You heal 2d8 hit points, and gain resistance to the next type of damage you receive until the start of your next turn.

- Weapon and spell attacks you make deal an extra 2d8 necrotic damage until the start of your next turn.

- For the next 8 hours, whenever you make an attack roll, ability check, or saving throw, you may roll a d8 and add the number rolled to the roll. You may benefit from this added roll only once.

The blood crystals become mundane and melt if they haven’t been used within 24 hours.