In episode 358, Danzo uses Izanagi against Shisui and steals one of his eyes, meaning Danzo had a Sharingan eye prior to having Shisui's Sharingan eye.
On the Samurai Bridge, Danzō removes the bandages on his right arm to reveal ten Sharingan eyes embedded on it.
Kotoamatsukami has a 10 year cooldown when used by someone other than Shisui. Danzo used it at the Kage Summit to try and become the leader of the coalition, but it was foiled by someone recognizing Shisui's chakra signature in his eye who used a stolen Byakugan. So, he just didn't have it as a possibility.
Danzo planned to use the kotoamatsukami on tobi/obito uchiha but was taken out by sasuke before that could happen.
At some point Shin became obsessed with the Uchiha clan, especially Itachi. His Sharingan-embedded right arm was harvested by Orochimaru and transplanted to Danzō Shimura along with some of Hashirama Senju's cells. Some time after this, Shin left Orochimaru's side and took most of his clones with him.
Danzo had the Sharingan for the same reasons Kakashi had it: Transplantation. Though, unlike Kakashi, who was willingly given his eye by Uchiha Obito, Danzo's Sharingnan were harvested from the victims of the Uchiha Massacre, which he himself helped organized.
Could the Kotoamatsukami work on Madara, Kaguya, or Momoshiki? - Quora. The answer is all in the name, “Kotoamatsukami”. And that answer is absolutely yes. Kotoamatsukami means “Distinguished Heavenly Gods”.
Beerus is one of the strongest Gods of Destruction in all of the universes and there is no evidence to suggest that he might not be stronger than Ultra Instinct Goku and Jiren. With his Destructor Energy, he is almost unbeatable.
Prime Rayleigh is stronger than Shanks.