Where can I find mage from Umkas?

[Petwin]

I don't know any other combination of dungeon crawler and turn based strategy (TBS) game that works so well.

If you can manage RTS instead of TBS, a game you might like is Warcraft III - Reign Of Chaos and its sequel Warcraft III - The Frozen Throne. A bit less, but still very satisfying is SpellForce 2.

If the TBS-part if the game is what thrills you, try Elven Legacy, its predecessor Fantasy Wars, or good old Fantasy General.