I actually that i was good at hammer till i saw this. I honestly stopped using hammer against fatalis bc i thought there were too many openings to hit me n i was carting so i played a tanky lance support. This vid really shows me how i play incorrectly n how i should utilize those combos he uses a little more.
Thing with hammer is learning monster patterns so you can be in the right place to punish at the right time instead of living a life of chasing the monster around.