There's a video after the break of God of War II QA lead Stephen Peterson showing you how to get the "15 Min Fight Scene" Trophy in God of War Collection. There's a 500-hit combo in there.
Stephen's played through God of War II "probably about 100 times". He shows which magic to use, when to use it, and how to get the best from your hammer. As if you need telling that.
You'll also see a "flaming vortex attack" that does "massive damage" to "everyone".
Don't take our word for it.