Briar, Living Weapon

Vigilance, Lifelink
When any creature dies during Combat Phase, Put a +1/0 counter onto Briar.
Briar enters the Battlefield tapped and doesn't untap during its controllers uptap step.
{b}Sacrifice a creature: Untap Briar and put 2 +1/0 counters onto Briar
{r}{2}{t}: Remove all counters on Briar, deal {x} damage to target creature where {x} is the number of +1+0 counters on briar