Could anyone explain how this ability is meant to work with regards to how often kel'thuzad can cast it?
I understand that when he casts it on a player it will chain to any player close to the original target as well as from any player near to the original target. I didn't realise he could cast the spell TWICE on a 2nd target that was over 30 yards away from the original target either at the same time or within 1-2 seconds.
What basically happened was that kel'thuzad cast frost blast on the melee and because the boss moved a bit (due to tank knockback I think) 5 or 6 melee got it as they lost their spreading a little bit. At the same time as all the melee got frost blast 1 of our hunters also got it even though he was nowhere near the melee... i'd estimate he was 30-40 yards away. All the melee survived but our hunter died (probably because the healers got overwhelmed with so many getting frost tombed at the same time). We tank kel'thuzad at the throne where he becomes active while me and the other hunter were on the far side of the green circle that is in the middle of the room so it definitely wasn't a result of the melee frost blast chaining over to the hunter.
The most annoying thing is that we were on for immortal at the time and this frost blast death was our only death on that naxx clearance (the 4th time we've failed with 1 death now)... We really aren't getting any luck with this and losing it to what seems a bug or something very unusual is quite painful especially when it's been the only achievement we've needed for our black proto drakes for at least a month now.
I must admit that I thought he did frost blast on 2 different targets every time he cast it but people in guild said this wasn't the case and that he should only do it on 1 target (unless it chains to another player).
I will try and post the wws when we find the event in the log.