>You need to catch Reshiram/Zekrom because you're the hero it chose and you need to have an epic legendary dragon showdown with N
>You need to catch Delta Episode Rayquaza to fly into space to stop the meteor
>You need to catch Solgaleo/Lunala because Nebby's been through enough shit and you'd be a heartless bastard to leave it alone
But why do we need to catch these? They're just a battery for the magic nuke. Wouldn't knocking it out stop it just fine? And to make it worse, having the legendary completely trivializes the following Lysandre fight, especially if you have Xerneas.