Averial Mage

Spellcasting. The mage is a 10th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). The mage has the following wizard spells prepared:

Cantrips (at will): Dancing Lights, [Tooltip Not Found], sword burst, Mind sliver, Mind sliver

1st level (4 slots): mage armor, magic missile, shield

2nd level (3 slots): Warding Wind, Tasha's Mind Whip,  Blur 

3rd level (3 slots): counterspell, thunder step, haste

4th level (3 slots): greater invisibility, stoneskin, storm sphere

5th level (1 slot): Steel Wind Strike, far step

Rapier. Melee Weapon Attack: +8 to hit, reach 5 ft. one target. Hit: 8 (1d8 + 4) piercing damage.

You can attack twice, instead of once, whenever you take the Attack action on your turn. Moreover, you can cast one of your cantrips in place of one of those attacks.

4 times per long rest, you can use a bonus action to start a Bladesong, which lasts for 1 minute and grants you the following benefits:

You gain a +4 bonus to your AC, your walking speed increases by 10 ft., you have advantage on Acrobatics checks, and you gain a +4 bonus to any CON saving throw you make to maintain your concentration on a spell.

It ends early if you are incapacitated, if you don medium or heavy armor or a shield, or if you use two hands to make an attack with a weapon. You can also dismiss the Bladesong at any time you choose (no action required).

When you take damage while your Bladesong is active, you can use your reaction to expend one spell slot and reduce that damage to you by an amount equal to five times the spell slot’s level.