Markos, the Savior

As Markos enters the battlefield, choose a color.
{w}: The next time a source of your choice of the
chosen color would deal damage to you this turn,
prevent that damage.
Heroic — Whenever you cast a spell that targets
Markos, put a +1/+1 counter on each creature
you control.
Sacrifice Markos: Destroy all creatures.
They can't be regenerated.
During your turn, your opponents can't
cast spells.