I'm sorry to hear that you tang died. It's pretty unlikely that he died from a lionfish sting, as the lions are fairly passive fish. Even if the tang were brushign against him, the lion is not likely to have attacked him, and certainly not repeatedly. The "welps" that were on the tang may have been from ick, as it can conglomerate into spots that will be more severe than the rest. This would also explain why his color faded. Lionfish stings are not very severe, they are meant to be more of a deterrant than a killing defense. In fact, I got sung by my black volitans just this afternoon while removing my sailfin tang from that tank. I guess I should have paid more attention to where he was. lol The venom in a lionfishes dorsal spines is nearly identical to a bees venom. Not very powerful, it does hurt a bit, but is not lethal. Even if the lion had stung the tang once, the tang would surely have known not to go back for more, and would have stayed far away from the lion from then on.