Bloody spirit gives about 400 attack power right? And Art of Fierceness gives 400 add damage? What is the difference between the two? Is one better than the other?
Attack gives a bonus Cabal Alz to Attack, which once total amp is added in, gives you your base dmg. This determines how hard you hit initially on any give monster or character. Add dmg. Is separate from this, and is pure dmg added in. Final note: While crits may cause attack to be more useful dmg wise, add dmg is added in after dmg from base/crits is determined.1 attack 5 add dmg depending on what skills you're using.
Common misconception about aof with bl bm2, the skill does not add 400 damage to each of the 7 hits, it only adds damage to each of the four cycles. There is 4 for blader and most other melee classes. Thus your first claw hit may only get 180 damage and the second 220 as that adds up to 400 for the first cycle. It is not as fast and powerful as many people seem to think it is.
The 400 attack is much better, considering WA bm2 has innate amp on its attacks along with all your other amp boosting that number to well over the bladers add damage without even mentioning the huge bonus Cabal Online Alz criticals will add to it. As also stated add damage is only applied after the skills and thus won't be affected by critical damage and can still yield lower damage outputs.