Ok here is my theory
I belive that pain can use his chakra to generate electric and magnetic field,thus i think he is a thunder type shinobi.He can manipulate his chakra to the point that he can generate large barriers and negate attacks(atleast thunder type).
The first sign of his power to create a barrier:
Now the fight with kakashi:
I belive he used his rod to insurge some of his chakra into kakashi to well ill say
it roughly send him a static shock witch cause his chakra to went wild and
interupt his raikiri.
Now the second and final confirmation of his barrier:
We can see that it litteraly pushed kakashi away from him and disrupted the flow(path) of raikiri that was going at him,and we can see that it destroyed the hound wall,so basicily i belive he can destroy anything non organic in his barrier.
We can clearly see that kakashi's atack was negated i speculate that it's because it was thunder type but i cannot be sure because no one else has fought pain up until this point.But kakashi does state(atleast in this translation) that it negates all attacks.
Now the final and most important piece of my theory:
I belive that pain reversed the polarity of his chakra that was implemented in kakashi thus making him magnitized(as a magnet can pull metal objects).
He then use his own chakra and body as a conduit to make an even stronger magnetic force.So he could easily drawn him in his range.
So the conclusion pain can use his chakra produce magnetic,eletrical barriers and uses his chakra to weaken his opponent and to negate enemy attacks,due to these thing i belive he is a thunder-type user.
So this is my theory,sorry for not putting images it's also my first post...
So tell me your opinion on this