>>44290544As the other anon said, it's used to try and nuke an opposing Pokémon if you have nothing better and are gonna faint soon anyways. May as well try to take it out with you.
Alternatively, Lunar Dance or Healing Wish are instead used when towards the end of your tank's lifespan to ensure the next Pokémon you send out is fresh and hopefully ready to sweep.
Final Gambit and Memento are the worst ones though. Final Gambit deals damage equal to remaining HP, and since you're almost always using it at the end of a Pokémon's time on the field, it won't be much. Meanwhile Memento makes you faint to try and cripple the opponent's offenses, but unless they're the last Pokémon your opponent has, they can just switch.
