Arcanis, Maleficent Mind

{x}: Choose target player. That player adds X mana of any color to their mana pool.
Whenever that player casts a spell this turn using mana added by this ability,
Arcanis, Maleficent Mind deals 2 plus 1 damage to that player for each
additional mana spent beyond the first.
The best victory is one on your own terms.-Arcanis, Maleficent Mind