First of all, this post contains certain aspects about the Lich King fight and may therefore spoiler certain things. If you want to find them out on your own or by trying, you should immediately stop reading this post. Please correct me if I state any wrong facts during this post!

Hello guys,
some of my following questions have already been issued but I see this as a little sum up and help for those who try to get as many information as possible. Since we really sucked at Sindragosa and lost a huge bunch of trys there, I decided to analyse the encounter, learn everything by heart, see those things going on, that cannot be seen in movies but in raidlogs and stuff like that. Basically there are that necrotic plague debuff and the "thing" called soul reaper, wheter it is a buff debuff single spell or whatever. So here we go with my first "interpretation" and question.

From further reading I noticed, that this "debuff" is a disease with 5 stacks, which is rather important in my opinion. The tooltip says that this debuff causes an immense amount of damage to a player after 5 seconds. My first idea, ok of let's dispell that crap, in order to lose a stack and to save the targeted player. It clearly states that the debuff loses it's effect each time it jumps to another target, meanwhile increasing the lichkings power. The logs I investigated show, that the groups who already kicked the LK's a/& let the debuff jump on an incoming "Shambling Horror", in order to increase the damage done and (is this right?) reset the buff on the LK. If the creature dies, the healers keep dispelling the debuff until it completely disappears.
Question: Does anyone know how often he casts this debuff? It would explain why for instance Blood Legion could reset the debuff on the LK by applying it to an enemy NPC. Is this the right way to treat the plague? Or am I completely in the dark?

Second thing I recognized is the "thing" (I call it thing because with this post I try to find out what it actually is ) called Soul Reaper. First of all: He only casts this from phase 2-end right?The Tooltip states:
This "cast" is an instantcast, which means cannot be interrupted. It deals a huge amount of damage and gives a buff to the caster that increases its physical damage by 100% after 5 seconds. Hmm there is the first problem, the loggs I found clearly state that the Lich King does not have a buff called Soul Reaper or anything that increases his damage by 100%. What is this thing? Furthermore the tank does not have a debuff that increases his damge taken by 100%...In addition the average damage of this spell in different loggs varies dramatically. I don't have any clue why this is the matter. I would be really happy if someone could clarify this for me, since I try everything to prepare myself for this fight as good as possible.

Another thing are the spirits (the exploding? ones) in the last phase. I am not sure if I saw some of the not exploding but simply falling down after being killed. May this observation be right or does every ghost explode and deal damage to nearby units/increasing its shadow damage taken?

The last thing is not really a spell or something. I simply noticed that guilds who managed to successfully kill LK did a lot of tank switches. What for? One idea could be that one tank takes the huge amount of Soul Reaper, the other tank immeadiately taunts and manages to tank the 5 seconds of 100% more dmg with a cooldown or anything like that. But as you can see I am completely uncertain about that.

Thanks a lot for your answers, maybe I will find some other problems lateron but after lots of studying and dealing with numbers these are the only things that affect me right now.
Greetings
Floid