Zaxtos, Lightning Blazer

Zaxtos doesn't untap during your untap step
unless you pay {1}{w}{b}{r}.
{r}: Zaxtos deals 1 damage to target creature
and 1 damage to target player.
{r}{r}: Zaxtos deals 2 damage to target creature
and 2 damage to target player.
{b}{b}{r}{r}{t}: Zaxtos, Lightning Blazer deals
damage equal to its power to target creature.