It's impossible in multiplayer because for one people could easily take advantage if it, and do you have any idea how hard that would be to code for a game like Toribash? Even just basic coding knowledge will tell you it's a no go
As for single player uses, I like the idea, it would certainly be better than pressing r and going to the frame where you messed up, and redoing the move you wanted to do, because you may have forgot by the time you get back to it. As for the multiplauer again, it would just simply cause too many issues in multiplauer. Since in multiplauer it is not one person's screen you'd have to change, it could be a great deal of many people on a server, and could cause lag issues based on how well everyone is connecting to the one server. It just wouldn't work in multoplayer and would be too difficult to implement, but not so much for single player.