Keung is not actually Redfur's real child.
Redfur's real child died when her planet was destroyed. Keung is not a normal bear. He is "The Beast of Apocalypse" the one who destroys the world. But he is not the one who destroyed Redfur's home. He just pretended to be Redfur's child because he got curious on how to be love as a child by someone who mourns for her dead child.  Redfur was so devastated that the moment she saw Keung a.k.a the best of apocalypse she immediately thought he is her child. However, Redfur know he isn't her child but still care and love him like her real child.  Inside Kueng's body resides the consciousness of the sleeping Beast of Apocalypse. He will only wake up  when the world can no longer be save.

He will only see Aileen for a bit because he will collapse as soon as Aileen gets near him. 🤣🤣
He still can't endure the force of seeing a dragon. 🤭🤭🤭

However he and Aileen will be together at the end. When sejun and the gang can stay on Earth. Because when they enter earth, it puts restrictions on them. And Sejun will level up Eath too so they can stay for a longer time. If i remember correctly, the first time they go to earth with the gang without Aileen. They only have 1 or 3 hrs to stay. (I forgot sorry 😔).
And what's shocking is Sejun needs to burn all his tower coins as well as equipments just to pay the price of entering the Earth. 🤣