The thing is we’ve already seen the real Palpatine get defeated by Vader. This is a Cloned version, yes he has taken power from the dyad but it still feels like a rehash. Adding red “ultimate power” lightning indicates a much bigger threat and this is why Rey needs both Sabers and the force ghosts to defeat him.
In the version I’m trying to create, It’s Leia’s purple lightning that finally kills Palps which is pushed by the force of “All the Jedi”.