The evil cousin to
Elric of Melnibone. Their hard fights are described very thoroughly in the saga written by
Michael Moorcock.
The background of
Yyrkoon is that he is the cousin to
Elric and plots to take over the throne from
Elric. He's the evil counterpart to
Elric in the Melniboné saga and thus accordingly stresses strength, raw power and a more conservative approach than
Elric.
Yyrkoon uses the runeblade
Mournblade, brought to Melniboné centuries before
Elric &
Yyrkoon were born. The other runeblade is
Stormbringer which Elric carries with him.