Thanks for your answers. I didn't know Betty had such a useful AW (don't know how much % is her "moderate" instakill chance, I'd assume around 25-30%). I've decided I'll just max lvl Lyla for the time being (after maxing other units' lvls such as Odette) and decide later on the SU thing. I'll dump my fairies on Odette (I'm also always using here and Garania if a second one is needed, better use that Lyla which I use in certain maps only).

I hope those three fairies I have turn into 3 SU.