it's pretty surprising but once you reach 5 stack he is pretty much max buffed...6 stack only adds 100k more hps and 7 stack another 100-150k hps. He still hits for the same too.
Quick question: we just killed him at 3 stacks last week and were wondering if we need to have the mask equipped (ugh, more MK-6 kits and mods swaps) or if it will protect us from his +5 stack via being in our inventory.
Also, stacks 5-7 are the same except for a couple hundred hps? This makes me