Heh, sorry - I got a little single-minded there and forgot to give you any feedback on the actual story!
In short, I enjoyed reading it. Skin-rip TFs aren't everyone's cup of tea, but you pulled this one off well enough. The build-up of the beast breaking free from her is better than the execution of that method in, say, "Cat People". Your usage of the characters was good also - not that you really had much of a choice, with Cheetara and Kit being the only female Thundercats (aside from the secondary ones from the later seasons that nobody save the fandom really remember, of course).