Arcane Deflection. When hit by an attack or failing a saving throw. The War Mage can add +2 to its armor class, or gain a +4 to its saving throw as a reaction. If the War Mage does this, it can cast only cantrips until the end of its next turn.

Durable Magic. While maintaining concentration on a spell, the War Mage gets a +2 to its armor class and saving throws.

Spellcasting. The Aeillan War Mage is a 10th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). The War Mage has following Wizard spells prepared:
Cantrips (at will): Fire Bolt, Frostbite, Toll the Dead, Blade Ward 
1st level (4 slots): Thunderwave, Burning Hands, Mage Armor, Shield 
2nd level (3 slots): Scorching Ray, Mirror Image, Warding Wind
3rd level (3 slots): Fireball, Counterspell, Dispel Magic
4th level (3 slots): Banishment, Wall of Fire
5th level (2 slots): Cloudkill

Action Melee Attack. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 2) piercing damage. 

Action Ranged Attack. RangedWeapon Attack: +5 to hit, range 30/90 ft., one target. Hit: 9 (2d6 + 2) piercing damage.