no, soul of steel isnt really worth doing, i hate it.
soul of a blacksmith, you collect the 3 things he needs- the funny stuff in forest, the dragon fang and a mineral/rock. when you collect the mineral/rock, go to cave 3 and run around. you'll come to a circular room with a switch in the middle, and purple rocks around the outside. this is where the C3 mineral is, its not obvious like in 1 and 2. run round the edge of the room and you should get the mineral. some people say you must kill every forest enemy for the mineral in C3 to appear, this is not true!
After that, go back to montague, select the hunter type weapon, and you'll get a god hand. also, he likes giving out weapons with hit, which is nice

(the gun is a suppressed gun, cool, but not nearly as good as god hand and the FO wep is a technical crozier, which sucks. barta lvl 4 as its special... no thx >.>)
n.b.- after getting the weapon, even if you quit it immediately, you cannot get another weapon. if you do it again you'll get a blizzard sword or whatever. the only way to do it again is to reset without saving.