@MrASSH0LE: The 6 Paths are his other 6 bodys, he does not have them. Thats why Nagato was called the 6 Paths of Pain, he had 6 bodys each representing a different path. Hence why there will be no Biju Dama here. Or in laymans terms the only reason he can use the Biju Dama is because he used the bodys of Jinchuriki as his 6 paths, with out them he cant use it at all. He would still have be able to use the standard rinnegan powers, like Shinra Tensei and whatnot.
Tobi will be waiting a very long time for him to run out of power, need I remind you that he was fighting off an army of people when he was losing that number of souls. And Tobi's greatest feat of destruction is that of building level, without his 6 paths. Not to mention his durability is around the same. His attacks will make no significant change to his PS at all. Now while he does have the Rinnegan, the only real difference it could make to the combat side of this is Shinra Tensei, but once again he would need to be tangible to use it which would put him at the mercy of Father again. The only way they managed to kill him was Greed altering his skin to a more brittle substance and then Ed punched a hole through his chest allowing the Xerxesian Souls to escape. Unless tobi can replicate that I cant see him doing any damage to Father.
Father would sacrifice one or more of the souls in his PS to open the gate and either use it for transportation, or to learn the truth behind Tobi's dimension and a way to escape.
Strange, I watched the 2003 and version at least 3 times I dont remember him saying that (Could have just forgot), Ah well I can alter it. The PS allows him to bypass the laws of equivalence, allowing him to transmute any substance into another substance as long as he has the souls to do so. Air is a substance and is suceptiable to this.
Or this (pulled this off the wiki, since I thought it was worded better there) (And wow why did I not just say this in the first place lol)
Made of "pyrotex/ignition cloth" and embroidered with unique flame alchemy transmutation circles, these gloves create a spark when Roy rubs his fingers together and allow him to manipulate the concentration of oxygen in the air surrounding his target, raising its density to a level at which it becomes a volatile and flammable oxidizer, and creating narrow pathways of oxygen through which he can direct the ensuing flame that blossoms from the spark. The 'snap' sound is caused by the instantaneous speed at which the highly concentrated gases and sparks react together and pop (not his fingers actually 'snapping', to common belief.)
He has summoned Kurama, that much is true but, as we saw from the real Madara he cannot summon it unless its under his control, which it is not unless the OP allows it to be. Besides by the time his hand hits the ground to summon it, he would be impaled through the chest by the earth, which Father just transmuted.
Also some of the alchemists in FMA are above Tobi in some areas, given that he is not very destructive or durable. But he does beat them in speed and stamina of course.