My idea is for SOME legendaries like Groundon to be treated like an awaken angry Pokemon or... Like a Boss. Imagine if when an Groundon showed up, he started destroying stuff around? Or when an Yvental spawned, he was basically a Wither, destroying everything around non-stop... That would be amazing! It would make the Legendaries different and even more believable, instead of a giant AI getting stuck between blocks and dying of collision damage.
SOME Legendaries could also quickly defeat wild Pokemon around them, making it hard for the player to play and giving them a reason to stop that raging thing.
-Again, Yvental could act like the Wither, where you have to grab your best team and try to defeat/capture it while it's destroying stuff around by throwing explosive balls.
-Groudon could act similarly, but not flying, y'know...
-Kyogre could wipe the wild Pokemon on water, making for the player a living hell wheb they're trying to fight/catch water types.
-Psych Legendaries could make wild Pokemon around them be more agressive ( Following my suggestion on earlier posts ).
-Electric types could make the weather go crazy and always be throwing thunder around, damaging the ambient.
... And more!
Of course, not all legendaries are dangerous, some a peaceful or scared, and that's could make a play too! Some Legendaries could simply run away everytime you get close, some could telepeort like Abra, some could get angry at your presence and attack the Player, making it hard for the player to simply catch it, etc...
All of that to say that the Legendaries, currently, aren't dangerous or feel alive/believable. The playaers should be scared/cautious of even trying to get close to them, but as it is... You just throw a normal ball at them until you catch it.
That's about it, see y'all in the next post!