From the wiki: Many cards have the identifier “unique”. Characters are unique if they represent characters in the Bible with specific names, have “The” in the title of the character, or otherwise have a “unique” identifier on the card. All Fortresses, Artifacts, Curses, and Covenants are unique cards. Players may only control one of each unique card in his territory, set-aside area, or his side of battle. Different cards that represent the same character are also considered unique with each other, even if aspects such as the title, brigade, abilities, special abilities, card art or reference are different. (emphasis added)
If this is correct, then King Abijam can block another player's King Abijam.
