I'd actually say this.. but Lacus has good intentions for the Human Race, but sometimes those intentions grow, and sometimes bend even the straightest people. I don't know if the writers will grow a pair and turn Lacus
heel, it's basically the same reason why Cena is still
face right now. But I don't know, the best way you could turn Lacus evil is to:
With regards to Fllay though, my simple wish is just to remind people that she's still there, protecting Kira from unseen forces or whatnot. It would've made sense for Fllay to appear in ep. 39 but, the biased people in the writing staff put an end to that...