All right, this is weird, but who else thinks Petaltail (Petalcloud x Stormtail) could've been a thing if Petalcloud had survived the Final Battle ("Final Battle" sounds very Ninjago-ish lol). He was very devoted to her before she died, and I don't think he ever cared very much for Nightwing being her mate. Petalcloud may have been almost entirely evil, but appointing Stormtail her top Ice Warrior means that she trusted him at least a little bit. And he was so devoted to her that he took in Riversun after her mother's and father's deaths (which I think would've been pretty traumatic for a filly that young) and she might have had anxiety issues when she grew up, and it says a lot about his relationship with Petalcloud that he would be willing to deal with that.
Anyway, those are just my thoughts, and I thought you guys might like to hear them!
P.S. Wow, a lot of run-on sentences... I'm usually better than that!