I'm gonna say what I've been saying for three and a half years- the story potential, the headcanon/fanon potential, the artwork. I've always been more on the fictional and lore side rather than the gritty stats and strategy side. The fact that new releases are regular means that there's always someone new to find out about and you're not waiting ages for possibly your newest favourite character, though it also means that you're not too far away from your potential newest worst Nightmare either. And close friends through the game know exactly who I'm talking about here. XD
I also love the fact that UR brings people together in the virtual world and in reality. I say reality as well because UR brought me and my fiance together- I was working on a Jaxx cosplay for an event, and had UR not released Jaxx when they did, I probably wouldn't have gone to the event (I wouldn't have gone had I not managed to finish either, glad I did!) and then we wouldn't have met. I think it's sweet how he's the only RL person I know who knew what UR was before I told him.
the only thing that make me stay after 6 years in UR? not even sure anymore lol..
at first is the release, every 2 weeks, new release, time to make more money
then the community, used to help a lot, but yeah, after 2 years in the forum, got too many RL problems, then got tired too
and then everything just gone down hill. so many things happened, my goal destroyed (Lyse Teria Cr now is pretty much useless card that cannot be used in any format), Cr lottery for DT destroying my investment
I don't even bother to remember then name of new cards anymore since they have such strange names like jshkjshdkPAH or annoying el / la since they are wrestler such as EL xyz, LA blabla.
now I don't even care to buy new cards anymore (so much from legend with 51 out of 68 Cr to titan)
maybe the only thing that keeps me playing this game till now is because one (yes only one) of my guild mate playing. we chat a lot via YM and now, whatsapp and keep reminding each other of new cards, Cr, or LD.