Negris had originally intended to find the Undead King, but Ange didn't seem enthusiastic about this. If he didn't come up with a plan, Ange would keep planting vegetables in his cultivation ball until the next life.
Oddly enough, Durken wasn't very keen either. He was more engrossed in various new alchemical formulae.
Despite being the King of Alchemy, the new world provided a variety of new materials. New alchemy could be developed from these materials, and there were many new alchemical ideas to draw inspiration from, enough to engross him for a while.
Without Ange's orders, Negris couldn't instruct Durken either.
They can't really farm vegetables for a lifetime, right? Negris needed to devise a plan to get Ange out, even if they didn't go looking for the king, it'd be good to get some fresh air.
Upon reflection, Negris discovered he was not too keen on finding the Undead King either. Mainly he was bored, he wanted to go play.