This comment just got me thinking about a Shakespeare-themed fighting game… something like Soul Caliber but with characters that look like they walked out of Cyrodil:
MacBeth
Fighting is actually controlled by Lady MacBeth moving his limbs around, Scott Pilgrim-style.
King Lear
Use to be a level boss, brings an army of drunkards with him, wanders his way to a ring-out.
Hamlet
Summons ghosts, chucks skulls, his controls randomly invert during gameplay.
Romeo + Juliet
If you can hold out against them long enough, they just kill each other.
Prospero
Wizard, mostly unbeatable but only playable on his island.
Other suggestions?