Molten Skeleton

{r}: Molten Skeleton deals 1 damage to target creature or player. Activate this ability only three times per turn.
{b}: If you control three or more skeleton creatures, Molten Skeleton gains first strike until end of turn.
{b}{b}: If you control seven or more skeleton creatures, Molten Skeleton gets +5/+0, double strike, and is unblockable this turn.