Lursa and B'Etor Duras

Valor - At end of turn, if Lursa and B'Etor Duras attacked or blocked this turn, put a +1/+1 counter on it.
{2}{g/u}{r}{r},{t}, Sacrifice Lursa and B'Etor Duras: Destroy target Human or Klingon.
"This is not a threat, Captain. Merely an unfortunate truth."
"So why be our enemy, when you can be our friend?"
Lursa and B'Etor Duras, to Picard