Your odds of finding a Commander table where you cant cast this just for R are pretty slim, and I could see this becoming one of those uncommons that fetches a fiver unless it sees frequent enough reprints
A 4/4 for four mana, Gisa states that when a creature under an opponent's control would die, those cards are exiled instead
Access Tunnel, Tetsuko Umezawa, Fugitive, and Skrelv, Defector Mite are just a few popular ways to guarantee that you can activate ninjutsu abilities
As if they didnt already do enough, however, Ashiok, Wicked Manipulator also has a passive ability that lets you exile cards, rather than paying costs with life
Vodalian Hexcatcher A cycle of mono-color lords was on my bingo card for DMU, but I wasn't expecting the merfolk lord to be so powerful