I wasn't very convinced by that 'ending'.
A few years later, Merlin encounter Alice again, which, this time, he's working at a bar to earn money for a living.
It is noted, that Merlin is extremely idiotic, and yet his arrogant, and rude nature causes him to act as a person who disregards and even sees that the surrounding's scolding, bragging, complaining, and insults about him doesn't matter since he met a lot of peoples these types, and got used to their grudges that are hailed against him.
Connections to the 1st Palace For some unknown reasons, Merlin's body is somewhat connected to the items inside of the castle, in which, whenever he's injured, an item would be break, it is demonstrated that whenever he is injured by something, his sister, would eventually notice that the item she's holding would break, hinting, that Merlin had some sort of connections with his own castle.
Being a Goblin King, he possesses a giant physique and is always seen wearing his royal robes and crown.
During this incident, he and his army were defeated by a powerful magician.