Spellcasting. Vajra is an 18th-level spellcaster. Her spellcasting ability is Intelligence (spell save DC 18, + 12 to hit with spell attacks). She has the following wizard spells prepared:
Cantrips (at will): fire bolt, light, mage hand, message, prestidigitotion
1st level (4 slots): detect magic, identify, mage armor, thunderwave
2nd level (3 slots): invisibility, misty step, web
3rd level (3 slots): counterspell, fly, sending
4th level (3 slots): banishment, fire shield, stones kin
5th level (3 slots): Bigby's hand, geas, telekinesis
6th level (1 slot): chain lightning, globe of invulnerability
7th level (1 slot): forcecage, prismatic spray
8th level (1 slot): antimagic field, power word stun
9th level (1 slot): imprisonment

Special Equipment. Vajra wields the Blackstaff (see appendix A), accounted for in her statistics. Roll 2d10 to determine how many charges the staff has remaining.   Magic Resistance. Vajra has advantage on saving throws against spells and other magical effects.