"Axelle's Bloodline Awakening" 

We don't have time to explore the truth to Abyss blabla whatsoever and so, let's just say it straight. 

The elves didn't know about Axelle's father's true identity and only knew that Axelle had the demon bloodline, but the higher-ups in the elven race must have known about it. 

Axelle was the Prince of the elven race as well as the Abyss Demon. 

No one knew how the king of the Abyss Demon could get in touch with the Elf Princess, but the elf princess was expelled from her royal status, and the Abyss King also gave his throne away before disappearing with the elf princess. 

Unfortunately, all of this was only until Abyss was tightly guarded, and the couple was separated, leaving Axelle in the Elven continent. 

Axelle never grew up with his mother because the princess soon died of too much miasma contamination despite being a blessed elf full of light attributes.