Help with Bo-Katan (Mand'alore) event?

Hello! My Kelleran Beq has 147k protection and 280 speed but gets demolished every time through. I can't find any guides post-relic delta, as it was apparently difficult but not impossible before. I usually manage to get through Fives and sometimes Rex, but most often get beat before I can even get to Rex. I've followed four different guides and it's been the same result.

I'm at my wit's end with this one. Any help would be appreciated.