Base damage: 2d6 damage. For every hit, you will do another d6 of damage. You also gain advantage on characters that have hit you before. You also gain a Blood Die.
Spend 1 Blood Die:
You can do another d6 damage on top of the one you have.
Spend 2 Blood Dice:
You can upgrade your dice to d8s
Spend 3 Blood Dice:
You can use your breath weapon on your sword and for the next 2 minutes have it do 3d6 damage as well
Spend 4 Blood Dice:
You transfer blood from the blade to another person, bolstering them. They get 4d6 temporary hit points
Spend 5 Blood Dice:
You instantly crit if you hit the person