I'm having some difficulty deciding what time of ending/final battle I want to write. The issue is that a main plot piece is the characters trying to stop someone from opening a prison and releasing a being that could destroy the planet. Should the battle end before the villain is able to open the prison or have the prison be opened and the main heroes have to stop this being? I've been building up that the being in the prison is super powerful, but so is the main villain. Would it be more exciting for the characters to fight this being and stop the apocalypse or have the final battle end with the main villain's defeat? If that makes sense!