In Episode 22 Lelouch told Euphemia he would make her shoot him. He said people only have room for one messiah. He said that the Japanese would see that she was a false messiah and he was a real messiah when he miraculously revived.
Any statement must be either true or false in reality,and either true or false in the mind of the person who said it (though it can be partially true, and is more likely to be only partially true or false the more complicated it is).
So was Lelouch's statement that he would miraculously revive true or false in reality, and true or false in his mind?