[spitsire999]

You'll need:

1. Paladins
2. Royal Griffins
3. Archmage
4. Phantom spell
5. (Magic Spring to replenish mana).

Combat sequence as follows:

1. Get a stoneskin on the Paladin
2. Move Paladins to attack Gremlion.
3. Put the archmage right behind the paladins (middle)
4. Move the Royal Griffins next to the Archmages, but with 1 cell free in between them (move them to the right side of the battle area) to allow Gremlion to put a tower down in between the Archmange and the Royal Griffins.
5. Use Archmages' arcane shield on paladin every time you get the chance. Otherwise use his trance mode.
6. Use Royal Griffins Heavenly Guard to get an extra ally. Do NOT use it to attack Gremlion. Use it to take down the towers in 1 turn.
7. Use Royal Griffins to kill the gremlin towers.
8. Phantom Paladins as the battle goes along to resurrect fallen troops (from Gemlion's Area of attack).

I used these three units and this strategy on impossible mage no loss. I had 35% physical resistance from items and only 25% magic resistance (Anti-magic diploma). All of these units have inherent magical resistance, so you don't need much more. Furthermore, I had even less intelligence/mana/mana reg than you had (4-6 mana reg per turn, 24 int, 100ish mana) and I beat him on turn 30-40 or later. Basically you just get the paladin/paladin phantoms/archmage to hit him and wear him down ever so slowly. To finish him off, remember to make sure all your units are rezzed and finish him off with the Griffins or whatever unit has a turn after the paladins in the last round.