@Umetsu Yeah but that was author simplifying the skill experiment in one go.
As he don't know what the skill would exactly do, he would need to safely test it out a lot like any of his other skills.
He only want to test this skill to possibly unlock the wizard class so why not do it with the least risk possible.
This time the author made him do a blunder to quickly show to what extent this skill was dangerous and conclude the experiment.
We would probably never see he use this skill ever again.