The Ultimate Hand was quite intriguing.
It wasn't the simple and crude "fusion" found in novels, nor was it a creation of the so-called System. The Ultimate Hand was like a gun that shot a special "glue" that bonded things together to create something new.
That is to say, the Ultimate Hand required a casting action. Just like Zhou Li had to activate the Ultimate Hand first, then raise his hand and use his thoughts to drive the "glue" within the Ultimate Hand to adhere to two things he wanted to merge, and finally initiate the Ultimate Hand.
In simpler terms,
apply some glue first.
Therefore, the moment he saw the cunning stone-person, Zhou Li's expression changed.
Apply some glue first.