Zelex was once a happy little kid, until another planet(Fendoria), came to conquer and annihilate their home planet(Shrilanite). Once they saw their friends and family dying before them, everything changed. As they watched buildings be leveled to the ground with lasers and bombs, they didn't know what was happening, or what to do. All of the planets forces were being killed in cold blood right before them. 

Shrilanite was a peaceful planet. They weren't prepared for things like that. Their parents shoved them into an escape pod, forcing them to flee to a new planet, and that planet, was ARCADIA. They ended up alone and isolated for a long time. Until they met Kazuto, and Quixel.

 Kazuto and Quixel took Zelex in as a friend. They helped her get back on their two feet, and Quixel got them a bartending job, while Kazuto helped them get clothes so they could feel more comfortable in their body. Quixel helped Zelex get an apartment, even with a discount for it. Quixel helped Zelex for many years, and they got together after a while, which Imser and Kazuto tease them a lot about because the two are awfully stupidly cheesy... Ever since Zelex was sent to ARCADIA, they've always been happy and energetic in public, yet quiet, and seemingly depressed at home. But can you blame them?