I'm sure there are a number of ways to do this (especially now that he's only 15000 health now).
First, let's discuss his cheats.
1) If you cast an aura, he free casts Adapt aura.
2) If you cast a blade, he steals it... actually, he steals all blades from all wizards.
3) If you cast a universal trap (feint/hex/curse), he casts a sacrifice.
Currently, I'm geared with high critical, and in the fight, he did block a lot, but some of the critical hits landed. I was lazy and didn't want to change my deck too much, so I assembled it as such:
(Horizon Hold Deck of Furor)
Meteor Strike x5
Raging Bull x1
Rain of Fire x1
Power Link x5
First off, this was a sloppy build. The Raging Bull should have been replaced with one or more Fire from Above. The Rain of Fire is OK, but requires so many pips; I should have probably swapped for FFA too.
I don't have Krampus, Brimstone Revenant, Burning Rampage, or Hephaestus. Those would have been better picks over the Meteor Strikes. Other options for Meteors would have been either Sunbirds or Phoenixes. Sunbirds would have come out faster, but I would have had to load even more sun spell enchants in. Helephants would leave too long between hits, although if you were playing with more traps than I did, that would help out. Immolate is too painful for me to cast. The point of the deck is unloading a lot of spells and maintaining enough pips for constant damage while keeping my health above zero. I've used this kind of deck before too nice effect, and it worked here, despite my sloppy build. Power link with the empowerment and critical gear definitely worked out well.
Were I to try this again (and I may), I might opt for something like:
Fire from Above x3
Fire Trap x4
Potent Trap x2
In terms of Combustion vs. Wyldfire, I did notice an uptick on my critical hits with the Combustion cast. If you're not going for critical, or if your critical chance is already high enough, Wyldfire is the better choice. Hephaestus and Brimstone Revenant are good builders if you have them.