I used it to kill the Judge, Jury, and Executioner before setting them off, actually. Well, less so the Jury due to the +10 RES disallowing its death due to limited Bolting uses, but Lilina can 2-shot the other guys just fine. That probably makes handling the 'boss rush' a lot easier than it was intended to be since Shigeid can just Swordslayer the nuts off of the remainder, and Wendy isn't really threatened by any of that stuff either. Meanwhile, the magicians cover them from the back until Roy comes along, where they poke him and let Shigeid finish the job.
I never felt as though I was really showing much favoritism towards Lilina. Sophia sets her up to finish off most of the early enemies just fine (the Archers, the Merc, the General), and then after that point she's maiming soldiers all on her own since they can't kill her one on one. Granted, she doesn't kill them in one round for awhile either, but it's not exactly pressing that she does. In part 2, she's one-rounding (or close to it) Warriors if your Fir no longer can, not to mention putting colossal dents in or outright killing Generals. *shrug*
I'll admit I wasn't trying to speed run it or anything, since pretty much everyone made it to level 20 sans Cath (bless her heart, but she's worthless in combat). That said, I think the characters and weapon levels should stay as they are.