Quick note: sorry these answers took so long, had a lot of stuff to do. But here are some answers to some good questions
Response to an unknown guest
I have not watched Solar Opposites, but I've heard of it.
I think the Citadel of Ricks would easily take care of her, maybe with something as simple as a portal gun.
I'm not sure about RWBY with the fighters. They'll definitely want to do it, but they might try to get Rex's and Five's approval.
Response to Tup
I like Fives, he's a really cool clone. I'm not sure if I have a least favorite, I love the clones and the 501st.
I don't read too many of those fics. Some of them can be entertaining at times, but I like fics with story, not just harems.
No, I like how Gregor died a hero's death. Hondo would do great business with Roman and Neo, I can't imagine a better business partnership.
Response to ARC-5597
I like John Simm. He's like Doctor Who's Joker, and his involvement with the Cybermen (my favorite villain) was perfect. As for least favorite, I didn't like Geoffrey Beevers. He was the same thing as Peter Pratt.
I didn't t like the Zygons that much. I just thought they were weird.
Oh, the Sontarans would be really interesting. They could definitely overpower Atlas, but also help them if the had an alliance. Against Titans would be interesting.
Response to another unknown guest
Huh, I don't know. That's a good question. Maybe Rose Tyler's mom would have made a fun companion.
Response to ZanyKnot
No, I was not. Thank you for telling me that, it's very interesting.
Response to Dr No
I think RWBY would be shocked at first. If they're smart, they could give the Doctor tests to see if he really is the Doctor.
Again, sorry for the really late response, hope you found them to be good ones.