Don-El is son of Dondra Klu-Ta and Nim-El, who is the twin brother of Jor-El. Don-El is therefore Superman's cousin. Don-El resides in the bottle-city of Kandor. Don-El helps Superman as the captain of the Supermen Emergency Squad (SA No. 5, Sum 1962). When outside of Kandor, Don-El has the same superpowers of Superman.
See also: House of El