Mowtom
I'm truly still meta, enjoy this acronym!
The other option is that you can lose to Uxie or Azelf. That way you don't despawn them the way KOing or fleeing would, but don't have to catch them immediately. I did this when I was a lot younger and catching Azelf was hard.In Pokémon Diamond Version, Uxie, Mesprit and Azelf do not need to be caught to advance the campaign. I would like to postpone catching them, but do they permanently disappear at any point? I was already bamboozled by the game once, soon I will get around to whining about Spear Pillar at (Little) Things that annoy you in Pokémon...