>>40914798I remember Shaymin and Darkrai well since they had quests attached to them that did cool unique things and made them a bit more memorable.
Arceus' cut quest was also really good in terms of creating atmosphere and lore around a legendary. Going back to where you saw the boss legendaries and seeing a fucking staircase to heaven rise was cool as hell, then it had a unique battle theme that was different to everything else in its intensity.
Compare this to Magearna, Volcanion, Hoopa, Zeraora, Marshadow. There is nothing ingame to make you care about them. The games these days are nothing more than springboards to market these mons in the anime, it's so transparent.