I would dump those beholders (I dump them at aprox. level 20, they aint putting to sleep anthing with higher attack or level that theirs so as a mage there is not much point), I would dump those giants also (they dont have any resistances except some useless %)
actually, I do that quest with paladins/black knight and red and green dragons. stoneskin paladins or BKs, depending what you opt for, cast mass lock because of gorguanas mark of blood and those birds spamming egs. next turn, phantom red dragons and use some more buffs on your units, depending on what is being target, you can also cast 2x20 mana phantoms of red dragons or BKs/paladins (ressurect + additional turn), you could use traps or demon portal later. Last fight in the arena is really hard but doable. If you just want a no loss game then do a invissible ED or go with stoneskinned black knight and some items boosting their morale defense/dmg, whatever. Make sure you stoneskine them asap, cast demon portals after dealing with locking mark of blood before that. Then just give infernal blade to BKs later, 20% additional fire damge witch lizzards LOVE to suck + their crticicall chance = GG. ressurect them with evlin later and thats it. It's kind of borring playing like that after you do it a few times
