Aegis of the Silver Guardian

- As an action, you can touch the book's cover and cause it to lock as if you cast arcane lock on it.

- It functions as a spellbook for you.

- While you are holding the book, you can use it as a spellcasting focus for your wizard spells.

- The book has 3 charges, and it regains 1d3 expended charges daily at dawn. You can use the charges in the following ways while holding it:
- If you spend 1 minute studying the book, you can expend 1 charge to replace one of your prepared wizard spells with a different spell in the book. The new spell must be of the   abjuration school.
- When you cast an abjuration spell, you can expend 1 charge to grant a creature you can see within 30 feet of you 2d10 temporary hit points.