Regret's Single-Shot

Regret's Single-Shot enters the battlefield tapped
and equipped to target creature you control.
{1}{ut}: Add one ".20-gauge round" counter to
Regret's Single-Shot.
{r}{t}: Remove one .20-gauge round counter from
Regret's Single-Shot, it deals 2 damage to any
target.
Activate abilities only if this artifact is equipped.
Use as a sorcery once per turn for any creature equipped with Regret's Single-Shot.
Equip {0}