Adaman is a character from "Pokemon Legends: Arceus". He is the leader of the Diamond Clan, a settlement of Hisui.
Adaman is the leader of the Diamond Clan, who worships a deity passed down in legends as the "Almighty Sinnoh", who they believed created time, and Adaman personally believes in the importance of not wasting the precious time that Almighty Sinnoh gave to them. Due to this, he clashes with the Pearl Clan and particularly it's leader, Irida, who believe Almighty Sinnoh created Space.
In Pokémon Scarlet and Violet, it is revealed that he has an ancestor named Perrin