|Gallery | Relationship | Quotes|
|Other names||Phoenix, Fenex etc.|
|Light Novel debut||Light Novel Volume 1|
|Manga debut||Chapter 15|
Phenex takes an appearance of a tall man who wears pants and a suit vest with a flame pattern on it as well as a black bow-tie, he always wears his mask and a hat. On his left arm, he has an accessory that takes the form of phoenix feathers.
When he first appeared in the Astrim and talked with Kazuki Hayashizaki, he seemed a wise and smart Diva telling Kazuki that he was in trouble, because of magic intoxication. He also acknowledges Kazuki as king.
Phenex made a contract with Miō at the same time as Koyuki Hiakari and Kazuki.
After Mio was mortally wounded in battle with Loki, Kazuki kisses her so he can do a full power summon and save her life. He was warned that he was risking his life doing to do so in his weakened state. But he did not hesitate to do so, earning him respect as a king. He succeeded in saving her life but fell deep into magic intoxication. He spoke to Kazuki while he was drifting in the Astrum and encouraged him to wake up.
- In demonology, Phenex is a Great Marquis of Hell and has twenty legions of demons under his command.
- "Phenex" may be another way to write "Phoenix" as both share the same Japanese pronunciation, Fenikkusu. This is also pointed as Phenex wears phoenix feathers.