One of the best scenes in the entire series is Fischig kneecapping Eisenhorn, and then Fischig getting killed-and-Daemonhosted for this treachery.
They'd better leave it in.
Its stupidly symbolic. Since Fischig were kinda being set up as Eisenhorns concious/moral compass.
To him the whole deal was a last ditch efford to stop Eisonhorn from ending as the corrupted Inquisitor they take out in book 1.
And of course he ends being shot and then used as a host for a demon prince.
I equally well like Aemos burning himself out stopping Cherubal. And dying with his trademark phase on his lips.
Or Maximillian confessing with his dying breath that he lied when he said they didnt mean anything to him.