What if we were able to collaborate events like urgent quests with a little side story. Kingdom hearts would be a good fit along with final fantasy (choice of game up to developers obviously) cause each and every one of those games has a relateable aspect to Phantasy Star Online 2. In all the kingdom hearts there is various ways to play even with magic aka photon arts, and then there is final fantasy with materia which is also like photon arts. The point is, these can be translated to PSO2 near perfectly under the fact that the similarity between fighting style and mechanics. All I’m saying is that it would be cool if any of those would do a collaboration event with PSO2 to get so unique looks for the characters and weapons.

FFXIV collab already happened in PSO2 complete with Odin in Urth's Fount https://www.youtube.com/watch?v=DfqbvDLfYi4 (he can still be found on the Japanese servers' free fields(expeditions) as random Emergency Trials F.A.T.E.s)

There was supposed to be a PSO2 collab in FFXIV but that has yet to happen.

Some time after The Sixth Angel invaded Maple World, it came to PSO2's version of Earth as a phantom, ARKS fought it in AISes so Shinji (who along with his Eva unit, Misato, Auska and Rei were also phantoms) could shoot it https://www.youtube.com/watch?v=GbAgmq2ywH8

Also ARKS at one point could hunt Elzelion https://www.youtube.com/watch?v=Yd-2bZipxPo unlike Odin, it didn't stick around though.

Yep, Evangelion even had story on par with normal story with cutscenes and all, previously Emilia and Vivienne also had some cut scenes, then at the least the operators would talk about each collab boss, but that was the bare minimum. Most anime collab had zero interaction with "story", I'd expect it's also more costly to get the original voice actors to voice new cutscenes, but the same excuse used on Evangelion could be used for every collab.

https://youtu.be/D2ONTy5docg

There's also been a few collabs that just added new lobbies in addition to cosmetics.

The Space Battleship Yamato collab also included a skybox scenery pass for MyRoom

They really should do more of those IMO...