Bladesong Augmentation

This spell can only be cast while bladesinging. You augment your own endurance and martial prowess with arcane energies. For the duration of the spell, you gain the following benefits: 

• You gain 50 temporary hit points. If any of these remain when the spell ends, they are lost. 
• You have advantage on attack rolls that you make with simple and martial weapons that you are proficient with. 
• When you hit a target with a weapon attack that target takes an extra 2d12 force damage. 
• Your bladesong does not end so long as this spell remains active, but it still ends early if you are incapacitated, don medium or heavy armor, or a shield, or use two-hands to make an attack with a weapon. 

Immediately after the spell ends, you must succeed on a DC 15 Constitution saving throw or suffer one level of exhaustion. 

At Higher Levels. When you cast this spell using a spell slot of 7th the spell's duration is 1 hour, at 8th level the spells duration is 8 hours, and at 9th level the spells duration is 24 hours and does not require concentration.