Well...grevious kinda single-handedly (with a lil help from droids) slaughtered all the nightsisters.
Since grevious is so weak in-game, it only stands nightsisters should be weaker....
And the whole army of the dead thing....was old daka...not mother talzin....if anything old daka needs a buff to ress dozens at a time, like in clone wars.... none of which makes any sense, that show ended nightsisters badly.
Maybe add a 3rd ability...
Army of the dead This ability starts on cooldown. (1 round) Old daka calls an army of dead that strikes targerted enemy 5 times and all others 3 times. For each dead ally this # doubles. Each strike from this ability is x% dmg of party leaders basic damage.
That would make daka as useable as boba fett and a high priority to kill ASAP.
Also...mother talzin did hold off mace windu and jar jar binks insane plot armour... so IF mother talzin comes to game, i really think she needs to be pretty powerful...her dark side sorcery was pretty wicked powerful, considering she nearly drained the force from an entire planet and all life on it...that's some sith lord level dark side sorcery (like naga sadow, darth andemmu, darth nihlus) and she only really foiled by jar jar...so yeah talzin deserves to be a bad beach.