i believe he is a chakra sensor/chakra controller.
his is the body controlled by the real pain who is controlling the other 5
it makes sense because in two examples he uses water to sense chakra far away.
1. the rain over the village to detect an intruder
2. when he touches the lake to realize that the frog isn't there
he was able to predict the attack because he sensed where the chakra was going when kakashi used chidori
it is because he can control chakra that he pulled kakashi in
he predicted the giant fists smashing down bc he sensed it at the last possible second once it got near to him.
the reason i think this body controls all the others is bc there was enough time for god pain to dodge it but not the other one and if they are all one mind being controlled by someone else from afar they both should have dodged. but if that is the body controlling all the others it makes sense why he could dodge.
Now Im not saying that God Pain is the real pain controlling all the bodies but that is the one being controlled by the real Pain and through it controls all the other Pain realms.
I guess his escape though could be due to one of that Pain's abilities. But I dont think that is the case because Kakashi figured out his ability before he vanished.