Charged Magic Bolt

You concentrate on a spell by charging arcane energy. If you drop concentration on the spell by taking damage the spell's canceled. The spell's damage starts at 2d8 force damage and add 1d8 damage by each extra turn concentrating on the spell, with the max of 10d8 force damage.

By every spell slot above 2nd used on the spell add 1d8 to the starting damage and the max damage.