Itachi’s Amaterasu is a nightmare for most opponents, but not Pain. The Deva Path can repel it with Shinra Tensei, and the Preta Path can just simply absorb it. That’s two simple counters ...

leading to the awakening of his Mangekyo Sharingan upon learning the truth about Itachi's sacrifices. This revelation fueled his rage towards Konoha, granting him powers like Amaterasu and flame ...