Hot take: making Icicle (Thomas’s “ice alter”) the villain, and having Thomas die while surrounded by his family loving him is a major cop-out, and Thomas himself should’ve been the main villain ✋ they literally revealed that Thomas unethically experimented on Caitlin, and had lines briefly calling that out, but then undercut that by a) having his evil ice alter be the villain and b) having him die without any animosity or complicated feelings from Caitlin. Personally if I’d written this arc myself, I’d have Thomas be the mf villain, not some evil alter.
Maybe “Icicle” could’ve just been Thomas (no real evil alter, just a villain persona), or friendly enough with him that their goals actually aligned (like Caitlin and KF in s5), and/or Thomas makes excuses for his experimentation and even uses Killer Frost against Caitlin (“you and your alter are friends now! See? It all worked out in the end. You used to trust me once, Caity. What happened?”). Like…she was already traumatized by this reveal, so take it all the way and show it!
Make Thomas the villain, let Caitlin be horrified and be torn between her love for her father and the realization of the horrible things he did, maybe she tries to excuse it with “no, the powers did this to him!” but Team Flash all know its not true. Idk!! Something like that!! You can’t just drop something like that and then give the person who did it a kind, happy death without repercussions 😭 wtf guys