I was thinking in a more instrumental theme for the game... Imagining the people entering the arena, then the mages... Something like that, well... made this XD

Mage Wars Match Intro
Maybe Lux Aeterna - Requiem For A Dream    https://www.youtube.com/watch?v=SLJllk-0o6c

Beastmaster (straywood)
Hercules: The Legendary Journeys - Main Theme https://www.youtube.com/watch?v=_ruotaD4EPU

Beastmaster (jahktari)   
Xena Warrior Princess - Main Title https://www.youtube.com/watch?v=SVsrX3LiXNY

Druid:
Okami - Rising Sun https://www.youtube.com/watch?v=VZxK58tPU4I

Forcemaster:
Tekken 5- Moonlit Wilderness https://www.youtube.com/watch?v=E7Iz_rI_ECY

Necromancer:
Halloween Theme https://www.youtube.com/watch?v=amZQdMtjNA8
   
Priest:
E Nomine - Padre Nuestro https://www.youtube.com/watch?v=pvG9VvsNgCk

Priestess
Lugia's Theme https://www.youtube.com/watch?v=ZqpXrDuLqE0

Warlock (Arraxian Crown)
DooM Theme https://www.youtube.com/watch?v=uf47DQj_2Gg

Warlock (Adramelech)
Vega Theme instrumental https://www.youtube.com/watch?v=0L4uPY-XEOU

Warlord (Bloodwave)
Warcraft II: Orc 1 https://www.youtube.com/watch?v=FIHWHiegTIE

Warlord (Avil Lord)
Call for Heroes https://www.youtube.com/watch?v=btbJnZ1weOw

Wizard
Avatar: The Last Airbender OST Itro https://www.youtube.com/watch?v=GZvsF9T2yyU

Climax
Shadow of the Colossus - The Opened Way https://www.youtube.com/watch?v=ZWB8P4jbsAA

Victory Theme
Surprise XD https://www.youtube.com/watch?v=-YCN-a0NsNk

If not sure... Guile Theme goes with everything https://www.youtube.com/watch?v=Iof5pRAIZmw