A small, limb-less creature eternally covered in slime, Pollux is a bit of a something to get used to. At the top of his head are four small antennae, and overall he's mostly varying shades of purple. He needs a lot of water, so Seth carries around a fair-sized bottle of water to dump on his head when he starts drying out.
Pollux, as it happens, is Seth's Other, or at least one of them. No one's ever found a losrian that has more than one Other, but Pollux thinks it's possible. There are dozens more Others than there are losrians, after all, so it just makes sense. In any case, it took Pollux a while to find him, but they came across one another while traversing through the Tiernan Wood, and have been together ever since.
Seth eventually ended up with a son, and Pollux helped raise him; you know, as well as a slime-creature can raise humanoid children at any rate. Atenra didn't turn out weird at least. Too weird. Seth later started dating and one day married Miss Livia, and Pollux was fond of her. They eventually decided they weren't working very well together, and were making one another miserable, and divorced on good terms. Now they're just friends, but they're pretty good friends, and Pollux is glad because they do balance one another well. They just don't work as lovers, that's all.
Pollux probably noticed it before Seth did, that Seth had gotten a crush on his fellow airship pilot, Daren. It took a while before he realised it, and they've talked about it a few times. Pollux insists Daren likes him back, but Seth never wanted to complicate things, being fine with things how they were, but Pollux always knew better. The Other was literally born of Seth's dreams, he knew what went on in that guy's head...
Whatever though. He'll either say it or not, and Pollux can't make him. In the meantime, they're listening to a creepy girl (Pollux knows who the creepy girl is, yes), and now they're in Suyis' tower in Pyxis. Well, could be worse. They could've gotten shot at.