Apollo had gotten this idea after the original Apollo Leone had taken over his body—a combination of all the Techniques he had learned and created, forming an ultimate power concentrated in his right hand.
At the time, he was terrified that he might lose an arm, unable to withstand such immense force. Fortunately, the original owner of the body hadn't used the Technique.
Using that idea, Apollo tried to replicate it. But alas, he didn't know how the original body had executed it. Whenever he attempted it, the Techniques would collide with each other, forcing him to summon them in disarray around him.
Of course, he could combine some of these Techniques, but not to the crazy extent the original body had achieved. The original owner could even remember and perfectly execute ideas he had casually thought of.
That kid was basically a cheat code, Apollo thought, recalling the original owner of his body.