Blue Abishai

Medium fiend (devil), lawful evil
Armor Class 19 (natural armor)
Hit Points 195 (26d8 + 78)
Speed 30 ft., fly 50 ft.
STR
15 (+2)
DEX
14 (+2)
CON
17 (+3)
INT
22 (+6)
WIS
23 (+6)
CHA
18 (+4)
Saving Throws Int +12, Wis +12
Skills Arcana +12
Damage Resistances cold; bludgeoning, piercing, and slashing from nonmagical attacks that aren't silvered
Damage Immunities fire, lightning, poison
Condition Immunities poisoned
Senses darkvision 120 ft., passive Perception 16
Languages Draconic, Infernal, telepathy 120 ft.
Challenge 17 (18000 XP)
Devil's Sight. Magical darkness doesn't impede the abishai's darkvision.
Magic Resistance. The abishai has advantage on saving throws against spells and other magical effects.
Magic Weapons. The abishai's weapon attacks are magical.
Spellcasting. The abishai is a 13th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). The abishai has the following wizard spells prepared:
Cantrips (at will): friends, mage hand, message, minor illusion, shocking grasp
1st level (4 slots): chromatic orb, disguise self, expeditious retreat, magic missile, charm person, thunderwave
2nd level (3 slots): darkness, mirror image, misty step
3rd level (3 slots): dispel magic, fear, lightning bolt
4th level (3 slots): dimension door, greater invisibility, ice storm
5th level (2 slots): cone of cold, wall of force
6th level (1 slot): chain lightning
7th level (1 slot): teleport

ACTIONS
Multiattack. The abishai makes two attacks: one with its quarterstaff and one with its bite.
Quarterstaff. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) bludgeoning damage, or 6 (1d8 + 2) bludgeoning damage if used with two hands.
Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 13 (2d10 + 2) piercing damage plus 14 (4d6) lightning damage.

This full creature's stat block is not available (not OGL).

Mordenkainen´s Tome of Foes
Blue Abishai