How is this set compared to gold set, is it worth making +12?
Black Blaze set isnt really good, the stats are slightly (and i mean slightly) higher than 71 gold set, i think it gave about 200 HP / MP more, and about 2-3 dodge rate more, with around 70 more Matk (if its even that high). Obviously with it being AA rank as opposed to A rank, it is ALOT more expensive to +, it cannot be cored yet... though i doubt it will be any better once it is. Also it's proc isn't anything special, gives about 150 Matk or Patk, and 6th anni HP / MP absorb for about 6 seconds.
Back in my day, people used it for a skin, nowadays only those who cant be bothered to get a set (who got the set during the event) use it.