I think he is too strong in the output and too weak in what he can take, seriously.
- 3 BP and restriction to Wizard equipment makes him die in one turn, once Morcar decides to attack him. That means, he has to stay in the background, or use the diagonal attack from behind as maximum. He is even more passive than the normal Wizard is; worse, he is forced to play passive, or he dies.
If I should develop the concept, I would give him 5 Body Points rather than 3; or some magical protection.
And then comes the output.
Combined Spells
Genie + Sleep = Lullaby: Cast Sleep individually on everybody in any room or corridor on the board.
This one is ok. The Genie has the ability to move to any Room and then cast the spell for you.
Tempest + Pass Through Rock = Cyclone: Cast Tempest on everybody in any room or corridor on the board.
This to "any room or corridor" is too strong. Should be line of sight, or adjacent Room through the wall.
Swift Wind + Fire Of Wraith = Backdraft: Fills any room or corridor on the board with intense flames causing a Fire Of Wraith attack on everybody individually, attack twice for targets vulnerable to fire.
Again, to attack any room or corridor is too strong. Anything that removes the necessity of moving the mage to a vulnerable position is just inacceptable if it is not very, very expensive or the effect is small. You pay the weakest spell of all to have this intense superdamage effect? It doesn't fit together entirely.
Additionally, the entire Room thing - it may be ok in most of the quests, but sometimes it is just too strong if there is a quest with a central room full of enemies. Maybe you can tone down all these effects to something between two or three models, which is sufficient for using two or three spells.
Ball Of Flame + Vail Of Mist = Fire Spray: Fills any room or corridor in sight with flaming hot liquid vapour causing a Ball Of Flame attack on everybody individually, attack twice for targets vulnerable to fire.
Again, the "any room" thing is too much, and the "entire room" as well. This costs two spells, maybe it affects two models in line of sight?
Courage + Rock Skin = Invigoration: Raises A and D by three each until the end of the targets next turn.
Let it be two dice and it is already good: You raise both values at the same time. This is good! Normally you have to spend two turns for the same effect, so it is better than to spend the two spells seperate from each other.
Water Of Healing + Heal Body = Rejuvenation: Fully restores BP and MP.
This is too weak. The two strongest spells in the list add up to the weakest effect. I would give them as combination either a stronger effect, or you could use these strong spells as payment for a real strong effect that you like to have elsewhere.
Fully Merged Spells
All Fire = Inferno: Attacks like Fire Of Wraith and Ball Of Flame using three dice on everyone in any room or corridor on the board, four dice against anyone vulnrable to fire.
Again, i wouldn't take the risk of the shoulders of the Magician: make it line of sight only.
All Air = Typhoon: Attacks like Fire Of Wraith and Ball Of Flame using two dice on everyone in any room or corridor on the board and causes them to miss a turn.
Here you have the Djinn, so any room on the Board would be good in this case.
All Water = Monsoon: Attacks like Fire Of Wraith and Ball Of Flame using one dice on everyone in any room or corridor on the board and causes them to miss two turns.
What's Water? Water is healing, sleep, veil of mist. You could possibly put a room at sleep or put veil of mist at all the group as long as they wish until some roll of some dice is failing or something similar?
All Earth = Quake: Causes everyone in any room or corridor on the board to miss three turns.
Healing, Rock skin, Pass through rock.
Why does this make somebody miss three turns? You could give each hero 1 BP and Rock skin for some turns?