I'm not to be taken credit for this. Sadly I could not find any name/nick of the original poster from the site I got this from. But I thought I'd share it.
Here is the link to the original post anyways, since I can't find the original poster's name.
http://www.playstationtrophies.org/game/god-of-war-iii/troph..."This trophy is a lot easier than it sounds if you know where to do it. There are numerous places to get it, but I'll list the one that I used: the fight against Hercules.
To earn Hit Man in this stage, break out the Claws of Hades. Make sure that you have not levelled them up past level 2 (keep them at level one just to be safe). You can only do this for the first two sections of the fight (when all of the skeleton warriors are around). During the fight, spam the + attack. It should grip one of the enemies and rip out some souls. These souls will float around, dealing damage even if you take a hit. They don't do enough damage to clear out all of the enemies but they do enough that it registers as a hit."
Here is also a video done by
PowerPyx showing the easiest way to get it on Titan difficulty.