I went on RC late at night on Friday to update stuff, then I found Saturday that RC simply vanished. I don't think I'm in any position to help getting it back on line.
It's true that RU is now also 18+ for characters and thus more similar now than before Dec. 2021.
The Black Van has been started by members of RC as a place to fall back on if RC went down. Black Van has the exact same contents rules as RC, which are now almost the same as RU, the exception being bestiality (allowed on RU).
The big thing I loved about RC is that you couldn't delete your profile, and it's the same on Black Van as far as I've seen; for me this is huge as I tend to delete my online profiles when I have a dark depressive spell. When the spell is over, I'm always happy to find my profile as it was before instead of starting back from scratch. My current profile on RU is the fourth generation.
I'm a lot more into story writing than roleplay, but I've seen there's a space for roleplay on Black Van too, and it doesn't surprise me, since the main admin there was an regular roleplayer on RC.