Tenser’s True Transformation (HB)

You endow yourself with inhuman endurance and martial prowess fueled by magic. While this spell is active your mind is shielded from most influences, to help you concentrate on fighting. Until the spell ends, you can’t cast spells, with the exception of cantrips, but can still maintain concentration and use your battle mode, while gaining the following benefits:

• You gain 100 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.
• When you hit a target with a weapon attack, that target takes an extra 4d12 force damage.
• You have proficiency in all saving throws.
• You are immune to being charmed, frightened, blinded and deafened and paralyzed
• You gain one additional attack, when you take the Attack action on your turn. 

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