There wasnt a change in hellfire, there was a change in sentinel. It mitigates about 30% less damage now. A good quick nock on archer will do about 700ish damage to ifrit, if you combo that in with keen flurry every time the 2 are up you can get some good damage out of it. Same with blood letter if you can get it to stick. For all the other classes, combos are near impossible to pull off and mistakes can't happen. 1 DD dying can cause the entire party to wipe without chainspell to raise people.