Crossover Events: Which were limited/Always available

Was just looking to see if anyone remembers which crossover events were limited time vs always open in game?

I'm specifically looking for the Xenomorphic Greatsword (It was a tail drop from the event boss). It's stats weren't very good but I loved the glamour for it, gave my banners a really unique look.

Also, what were some of everyone else's favourite Crossovers?

I don't think you'll be seeing that event again, I've also tried looking for it but to no avail. You can get the Big beetle 6 blade or the snakeskin spear if you're into those. Though their stats are also garbage...

Also the twilight event final fantasy crossover event is my favorite

The Snakeskin Spear is pretty cool, especially for rolling up to the jousting mini-games. Ooooh, I should try to arrange some mini-game tournaments like they used to do.

I remember the Final Fantasy crossover! I'm not super familiar with the the franchise but it was pretty fun to see whole parties of brawlers running through raids in the Tifa costume.

The Mount and Blade crossover had some good cosmetics for Paladin, Blood Warrior, and OG Warrior. Not very flashy but nicely modeled.

I miss the Danimals Dungeon...

I would very much like to know if there are any ways to get items from the (now seemingly discontinued) Nier Automata crossover? The little robot pets really remind me of Clank from the hit Ratchet and Clank series, and it would make me very happy if I could "snag" one of them for myself!

The Nier event should still be going? It's got tons of real important Nier lore and it would be a shame if it got lost for good