Board Thread:Theories and Speculation/@comment-30168130-20170115054258/@comment-4912646-20170115125605

The rods have sprouted out of Obito's right half at least three separate times. First when he awakened his Mangekyō and went on a rampage, second when Madara attempted to take over his body somewhow, and third when Black Zetsu attached to him for the first time, though strangely not the second time. Curiously, it always seems to happen when he's not in full control of himself, though it may be a coincidence.

As for the statue, it is the Demonic Statue of the Outer Path. Maybe the rods, like the chakra chains, are an Outer Path power, and the statue got its name from the fact that it can use (some of) the Outer Path powers. Back when Obito first used the chains, he said their binding power was "far stronger than Pain Nagato's Outer Path", which must refer to him piercing people with the rods. Actually, I'm pretty sure that line is the only reason the wiki lists chakra chains as an Outer Path power, so it's strange we don't apply the same logic to the receivers (or remove Outer Path from both).