Zick had changed after becoming one with his broken side. Before on Earth, he was forced by the others to live as a loser. It was not his own will.
But in this world, Zick was free. There was almost nothing that was pressuring his mind excessively. There were worries about the demon Lord but it didn't reach the level where he could only concentrate on that one thing yet.
Right now, he might be working keeping the demon Lord as the aim in mind but that would change after finishing him off.
Zick had already felt some ambitions and aspirations appear within him. It came in the form of him taking over the underworld to gain influence. It was better than becoming a ruler too.
Zick wouldn't face any restrictions while he did all the things from the underworld. As long as he did all the things in the dark there shouldn't be any problem at all.
'I would at least have a base and influence after taking care of the demon lord.'
Though there were still many problems with it.