What I wish was in UT pacifist

So, you all know that you can find Asriel in the first room of the game after defeating him, right? And during his fight, we can also obtain something called 'LastDream' that stays with us after the fight. When we use it, it says it 'came true'. What I'm trying to say is, if we take one of those to Asriel and use it after talking to him, our determination should be able to stop him from becoming Flowey again. I DON'T WANT TO LEAVE HIM BEHIND TOBYYY