Zack checked his skills again and considered them in a new light using the knowledge that he had obtained… it could be dangerous, but the best option appeared to be to destroy the whole world. Then, they can survive the end using his pocket dimension.
"This is probably something this world's creator didn't consider, but doing this will definitely make me an enemy out of them," Zack thought. "Even those with true magic can't create worlds with ease… I probably can't."
Zack tried to deal with the five minutes cooldown time of his skills, but they always got in the way. That was the only thing that made him slightly balanced, after all. Still, without that one, he could easily create a world or two in his pocket dimension, he just needed to use the right skills.
In any case, unless the process is quick and powerful, there was a chance that it might fail… the creator of the planet could also try to intervene, so Zack will only have one chance.