Party composition :
Kensai lv25
Viconia lv 22
Edwin lv 21
Jan Jansen lv16/19
Kerdon lv 21

In wild surge room, I have reloaded so many times, Really I don't know how can I win the challenge.

Help me plz...

Use critical strike abilities with your warriors to dispose of those planar hounds quickly. Make sure you buff everybody with Chaotic Commands beforehand.
As for the mage, set up for Edwin 3xRuby Ray Chain Contingency to be activated when character is hit on an enemy who hit him. Afterwards, pre-buff Edwin with usual buffs (SI:Abj, GoI, etc). When an enemy mage hits Edwin with Ruby Ray, the CC will fire and dispel her magical buffs. Than, with a little bit of luck, you will manage to cast Breach successfully right around the time your fighters deal with fighters and hounds.

Thanks a lot for reply, Critical strike works very nice!
But I can't find Chain Contingency scroll so I can't kill the mage so far...where can I obtain it?

If you are in the SoA part right now, go into the Adventurer's Mart and ask to see a special stock, 9th level spells are there. If you are in ToB, the wizard merchant (the one who asks to find his spellbook in Saradush) should have the spell available.

I found it! thank you.

A little cheesy, but I found casting "True sight" before entering the room to be very helpful as well - I think I left the dogs until last because they would respawn if killed while the mage was still alive. I also think (its been a while, so I could be mistaken) that the mage casts PFMW (not Abs Imm), and going at him immediately with improved hasted, protected from fire, critical striking, normal weapon wielders put a damper on his fun.

Yes, killing the mage first is a good idea. Also, protection form magical energy spell is rather mandatory in this fight (heh, captain Obvious ).

Imo, casting true sight is no cheese at all, simply because prebuffing before this fight is not cheesy. On the other hand, I'm not sure whether spells from contingencies should work in dead magic zone or should't.

What about sequencers and triggers. I never tested it, but do they still get 2x or 3x a wild surge or do they only get it once... or ideally, none at all? It could be a decent loop-hole if you only get one surge.

Contingencies definitely work. I remember using that tactic in my current run. Not sure about triggers, though. This requires additional testing.