It's fairly difficult. The easiest way to win the fight is to use silver. Celerity, Potence, and Fortitude are also very useful in this fight. So use those to your advantage. If necessary, you can actually avoid this fight altogether by using Walk of the Abyss.
Easy pickings....cast Prison of Ice, by now you should have that option. Prison of Ice leaves EVERY opponent in the game without a chance.
Does it work against every opponent? Geez, that seems kind of cheesy. Oh well, what are you going to do...
Yep, even in the final battle, maybe they have overpowered that spell a bit too much. Final battles are supposed to be challenging, if it's not too much to ask for. Not with Prison of Ice though.
I found the final battle chalenging even with prison of ice... Some opponents make it a bit difficult to even cast it...:/
You can also use your disciplines to steal all the warewolfs blood so he can't use blood healing and other disciplines. You can give all the party members flamethrowers. You can find a great deal of them in the tower ( anyway I found about 6 of them as far as I remember ). Whether they have ammo in them later or not you can sell them for the same price. Two party members stay fight, and one party member with awaken discipline stays at the back and resurrects any party member that falls down. If you have blood theft maxed out you have to use it only twice, and the warewolf is almost good as dead. It's good if you manage to steal his blood before he uses potence. In other case you'll have to awaken your characters a lot more .