Karmic Justice is based off of number of hits, not amount of damage.
For instance, I've had it trigger from rapid hits from hollows (one sword, one crossbow) that did next to no damage. I've triggered it (best use here) rolling through Crystal Homing Soul Mass where I took no damage. None. It caused a "hit" animation but since I was in an i-frame I had nothing done to me. The sorcerer on the other hand. Well, he got one heck of a surprise.....keh heh heh.
The best piece of equipment to maximize your Karmic Justice use, in my opinion....is the Grass Crest Shield. Added stamina regen which is nice but eveything....and I mean everything....counts as a hit since nothing is 100% damage taken.
I've also been killed by more methodical players and enemies trying to figure out the mechanics without it being triggered. They hit hard and less often.
So the key is fast and little damage to make the best use of it.
EDIT: My best estimate is that the KJ build up meter will go back to zero in three to four seconds max meaning you need several hits very fast. The least number of hits I've ever seen it take is five I believe. Soul mass coincidence?
FURTHER EDIT: Again, I have not tested it with the Calamity Ring so if you have and it appears to make KJ more effective there could be a hidden buff to it.
For instance, I've had it trigger from rapid hits from hollows (one sword, one crossbow) that did next to no damage. I've triggered it (best use here) rolling through Crystal Homing Soul Mass where I took no damage. None. It caused a "hit" animation but since I was in an i-frame I had nothing done to me. The sorcerer on the other hand. Well, he got one heck of a surprise.....keh heh heh.
The best piece of equipment to maximize your Karmic Justice use, in my opinion....is the Grass Crest Shield. Added stamina regen which is nice but eveything....and I mean everything....counts as a hit since nothing is 100% damage taken.
I've also been killed by more methodical players and enemies trying to figure out the mechanics without it being triggered. They hit hard and less often.
So the key is fast and little damage to make the best use of it.
EDIT: My best estimate is that the KJ build up meter will go back to zero in three to four seconds max meaning you need several hits very fast. The least number of hits I've ever seen it take is five I believe. Soul mass coincidence?
FURTHER EDIT: Again, I have not tested it with the Calamity Ring so if you have and it appears to make KJ more effective there could be a hidden buff to it.