A few ideas come to mind
I think theres room for things like:
Lycanthrope: Has ability/cost/trigger to toggle form.. wolfing out drastically altering mana and spell acess but becoming much more melee/health oriented, or even fully out of control.
"Monk/Jedi"- I use the term loosly, but inspired by a "jedi" style concept.. based around iconic style magic weapon that can deflect/redirect ranged attacks and cut through armor and such as obviously influenced by Lightsabers. To further reinforce the Jedi feel, the deck/archtype would have basic recreations of "force" powers but could choose to be light or dark (holy/dark) for its other spell types (ie jedi/sith) at deck creation. (much like the mage selects his element)
Vampire Lord: Count Dracula, Strahd, etc. You get the idea.
A Lich style concept where the mage himself is invincible but his "weakness" is contained in a zone or conjuration or something on the board, and he loses if that is destroyed.
Dragon Lord: Who doesnt love Dragons?
Reaver: Gets more powerful as his health total gets lower and lower
Spell Theif/Doppleganger: works off of or immitates the opponents abilities and spells.
Elemental: Not an elementalist, but literally a Fire/Water/Earth/Air/nature/stone/Etc elemental. (slected at creation)
Ninja: Stealth mechanic of being able to play creatures face down like hidden enchantments, to turn himself facedown to "hide" use sneak attacks and subterfuge and neat ninja magics ala shinobi. Lightfooted quick fighting mage with neat caltrop traps, smoke bombs,and ninja flavored equipment
Bard: charms and enthalls other creatures, etc.
Martyr/Guardian: based around taking damage and redirecting to himself on behalf of his minions to keep his creatures in the game doing things for him, rather than the traditional angle of creatures defending for the mage.
Other more traditional archtypes include:
Illusionist, pretty self explainatory. Illusions and trickery based
Enchanter, again self explainatory focuses on enchanting things
Artificer, builder.. works heavily through crafted goods (equpiment) and things like golems and clockwork minions