I wrote about Manannan in the very first Wizard Wednesday post. Mordack is Manannan’s more powerful but slightly less cool brother. Manannan has that mysterious “I might materialize and turn you into a cat at any moment” vibe that Mordack just can’t muster. Mordack’s finely groomed facial hair and much practiced evil glare lend him an aura of wizardly superiority. His summer castle definitely has an in-ground pool that he barely ever uses.
Mordack is the antagonist of King’s Quest V, which, much like Mordack and his brother, is more powerful but slightly less cool than Manannan’s King’s Quest III. The scenery is nice, and the puzzles are there, but playing as King Graham and his owl sidekick is not as cool as being Gwydion the rebel slave. This was shown to be true when King’s Quest VI combined the graphics and interface of V with the protagonist of III and ended up being super great.
Still, you should probably play King’s Quest V if you want your life to be rich and rewarding and just like mine.