I don't really have anything to offer you for pre-existing connections since both of my characters are from Harry Potter (but I may have Digory for you soon, so there is that), but in any case I look forward to throwing our characters together at some point and seeing how they work. I will try to give you a quick idea of who I have.
I have Marcus Flint (marcflint) is a 30 year od Field Combat Agent. He had a lonely, weird, mildly neglected and sometimes borderline creepy homelife which left him emotionally and educationally stunted. He was picked on for being "dumb", and learned very quickly to respond with violence. He left most of the wizarding life behind after Hogwarts, and travels around the world via motorcycle or freighter (when he has to cross oceans). He takes odd, very local jobs in the countries that he visits, and he rarely stays in one place for more than a few months at a time. I'm sure a Jack Kerouac comparison could be appropriate, but Marcus wouldn't get the reference. He also has a dog, Stalker, that might not actually be a real dog at all.
Delilah Moon (dlilah) is a 24 year old reporter for Atlantis News. She was a Hufflepuff in HP's year who was working at Witch Weekly writing their advice column, Ask Aphrodite before she ended up here on Atlantis. Her father is the pastor of a wizard church (Presbyterian), she had a decently happy childhood, and became an overly enthusiastic and optimistic adult. She always wants to give people the benefit of the doubt, and believes there's nothing that can't be done with the right attitude and a good song to keep you energized along the way. She likes to call people by the wrong middle name (ex: she might call him Lucifer Edmund Ricardo Pevensie in an enthusiastic declaration), and sometimes makes up her own words. She can be a little too much for some people.
On a slightly added note, Delilah also arrived on October 4. If they met early on she would have certainly been friendly, making some comment about how the newbies should stick together or something like that.
Anyway, I look forward to seeing what weird connections can happen in this setting. Hopefully we can try something out soon!