For devil fruit, I'm thinking the dragon-dragon fruit, ancient type, model tyrannosaurus. It will give him a boost in strength, speed, senses, plus the durability and healing factor of ancient Zoan. And when he Awaken his devil fruit, he will become even bigger in full form or hybrid. He could also use the same technique as Who's who in he manga(fang pistol, fang flash)

I bet Madara used the Izanagi and will come back, just like in canon.

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