Taxi is just a bad dude. Originally the child of an incubus and a leech he was believed to just inhibit the personality traits of the incubus. However, his personality is more of an emotional leech. He feels satisfied in causing people harm. Sometimes it could be through sexual devices but sometimes he just wants to drive a person to severe emotional harm.

A coalition of angels and aliens both agreed that he was too powerful and eventually he was turned into a Binturong to minimize his powers (with the belief that the smaller he was the less powers he’d have). Unfortunately this made him even more powerful. Eventually he had to get stuck into the lamp in order for him to stop his terror.

He stayed in the lamp for over 3000 years. Now I’m present day he was released from the lamp by Alma. As the very emotionally clingy and closeted gay Alma was he instantly fell in love with Taxi. Of course Taxi didn’t feel the same but used it as a manipulation to be completely free from the lamp. Alma freed him and he disappointed him severely. Through more deception he makes it to America, meeting Kyo, Posey and Chia in the process.

Just an FYI

Being trans doesn’t have a huge impact on his story being a magical being in all he just felt that being a male showed more power so he wanted to b a guy. That’s all nothing deeper.

Another FYI

He doesn’t particularly care for anyone. The only person he has strong feelings for is Kyo bc she’s a bitch and stopped him from doing what he wanted to do.