Poseidonia was allured by Oasis and often found herself taking breaks from her duty as a guardian to go and meet up with her and the other gilled/poison she hung out with. She felt left out when they would go into the ocean together, but she forced herself to try one day. Even though she almost drowned, Oasis saving her gifted her with the body parts of a gilled. She loved hanging with those two; she misses Oasis a lot, especially.

we learned so much from each other back then, didnt we? im honored it was all my fault you turned out the way you did! it was always a good time with you and olly, even if we were all so prickly to each other all the time, haha...! ... oh... how i miss you so my friend...

They weren't close in the beginning, both often beefing for Oasis's attention, but after becoming a cross sub they found themselves becoming more of friends. However, after Oasis left, Pose watched as in her eyes the man she knew started to become more deranged with these crazy ideas. She has tried to warn others, but no one seems to want to believe her. How is she supposed to be a guardian with him around?

you couldve made the right choice. you couldve taken the graciously extended branch from an old and dear friend, but instead you reject me and call me insane as if that would get oasis down from the sky? besides, nobody will believe the wild tales of an unpleasantly rude knight about a lonely, old hermit in a cave, will they? you used to have me, but now? you have nothing. and soon? youll have even less than that.