Senna, Kessig Huntress

Senna, Kessig Huntress and its abilities cost {1} less to cast or activate if an opponent controls a creature.
{1}{g}: Senna, Kessig Huntress gets +2/+2 until end of turn. Activate this ability once each turn.
{3}{g}{g}: Transform Senna, Kessig Huntress.