Matt, the Impetuous

At the beginning of each opponent's end step, if
that player didn't cast any instant or sorcery
spells, Matt, the Impetuous deals X damage to
that player, where X is the amount of mana spent
to cast Matt, the Impetuous.
Whenever you cast an instant or sorcery card, you
may choose to change its text by replacing all instances of "target" with "each."
"Shocking, isn't it?"