I've got a Jelly Angel too, to be frank I haven't used it much yet, but I can see it being an asset once I build up my non-dragon mons. I usually rely on a double ADK leader team to clear tricolour dungeons. There's something seriously satisfying about nuking everything in your path in one turn in those tricolour dungeons
Other collabs I could envision: Breath of Fire (more dragons!), Dragon Quest (this could actually be seriously possible?), Patapon (I think it'd be like the Taiko no Tatsujin collab
), and I can only dream of a Final Fantasy collab. I think GungHo negotiates deals with the company owning the rights to whatever franchise they collab with, so I'm just dumping all the cool + possible ideas out here now.
And I swear I might bust a lung if Animal Crossing mysteriously makes an appearance as a collab.
Monster Hunter is a serious contender since it's really popular in Japan, though working out a deal might be the tricky part. Too bad we will probably never see a Pokemon collab though
Maybe a Digimon one? Hey, I like that idea!
I also randomly want a tokusatsu collab and have giant monsters make an appearance. Just think how awesome it'd be to have the likes of Godzilla around
Or Super Sentai
As for new monsters, what pantheon have they NOT mined already?
They've got the Egyptian, the Norse, their own Japanese deities, the Hindu pantheon, the Greek, the angelic canon, some Chinese...actually, they could probably use more Chinese mythological figures
there's a lot more they haven't used >_> Hou Yi, Fu Xi, Nu Wa....just to name a few
The possibilities are endless
Completely random thought: Attack on Titan collab