Arthus - Tactical Suggestions

I'll start by mentioning I've only done this fight in 25-man, but the strategy should carry weight in 10-man. Don't get discouraged working through the phases of this fight. It will take many many wipes, and likely many many nights of working through the fight. Once you have it though, you'll really enjoy it.
First off Phase 1, I heard you made it through it at least once, refining it is essential, you'll have the pleasure of doing it every time you're working on the later transitions, and phases.

And 1st transition...

I'll add to this once you've had time to see the transition, or before you next attempt arthas.
I can't very effectively draw out phase 2, so there will be more talking, less pointing.
- Phase 2 is best described like a clock. A designated person with loads of situational awareness (good raid leader) will need to determine an angle of attack and the entire group will need to follow them. This will not be as critical for you in 10-man as it will be in 25, but good practice will help you later.
At the end of the transition the outer ring of ice on the arena will begin to glow, then fall away, don't be standing on it. Move in immediately at the end of the transition.
Arthas will return to attack you after the transition ends, the MT will need to retrieve him, and the OT will need to drag the remaining spirit out to the center. DO NOT run out in front of the spirit, allow the OT to continue to control its facing direction. There is a kill priority for this phase.
Valkyr > Spirit > Arthas
Using DBM/Whigs will be very important for the battle timers. 2 main things will occur while you fight arthas.
- A Valkyr will swoop in and pick someone up and begin to carry them toward the edge of the arena, this process is very very quick, so use chains of ice, snares, etc anything that will slow the valk down so you have enough time to kill it before it drops the person off the side. The Valk will always fly toward the closest side from the center, this is where the dedicated guide comes in. Their job will be to determine the closest position to the center the group can be, to force the valk to go where you want it to go.
- Defile, this is very easily a raid wiper. On a similar timer to the valks, arthas will cast defile on someone, at the end of the cast that player will drop a black spot on the ground, if anyone is standing in that spot it will grow, it can easily grow to fill the entire map, which is a wipe. DBM, and I assume the others will cause your character to say "Defile On Me" when arthas begins his cast, giving you a moment to react. You'll want to get as far toward the outside with it as possible, and everyone else will need to move away from you. In many cases you'll have 2 up at once, you preferably want it to look like the image below, keeping arthas centered, and the group fighting in the triangle areas, as close to the center as possible.

This will continue until you hit transition-2, it's very coordinated, sometimes you'll even have valk and defile at the same time, forcing everyone to pay very close attention to when to bunch up, and when to run away from defile.





Cool deal
I like having a diagram to look at . I think our tanks were positioned correctly, but our ranged were actually closer to the edge, so we were in a line almost, like so:
Stairs
MT/Melee - OT - Ranged Edge
Pillar
Does the triangular formation matter? Or can we keep it like we were? The main issue so far, to me anyway, seemed to be that the ghouls were dying to AOE, and thus not getting the plague and bouncing it to the horrors, so the horrors weren't dying fast enough. So then dps would switch to the horrors to take them down, but we'd have a newly-spawned horror up at the transition by this point, and the ghouls would be pretty much gone, so the plague was still bouncing to players.
Then we get to p2, and the spirits were killing people, plus I couldn't keep up with dispelling the magic debuff AND the plague one. By this point we'd wipe, right about as we'd get to the next phase.
No Worries
The positioning for the ranged shouldn't matter that much, there just happens to be a convenient little box on the line there to stand on. Visual cues are always helpful in very long fights like this, but as long as healers and ranged have no issue hitting arthas and tanks, and everyone can get the diseases to the adds in time then there shouldn't be a problem.
I can trim down the AOE.
Sadly, that would mean no more 16k on Recount, but I'll console myself somehow... :)
Consider it a good thing War :P
I see you at 16k and I feel obliged to let loose with AoE and 'catch up' if you will, but not sending out AoE's isn't an issue for me, I just like having high numbers :)
As for the Shambles...my understanding with them is that they will one shot any NON-TANK with their frontal spell they do (Which is why they are pointed away from the raid) and WILL one shot any tank when their enraged (They can be tranq'd or stunned here)...so IDK if you want to have anything enraged. Also another thing I noticed with the Shambles...do they have some sort of health regen? I had my DoTs on them for awhile on certain attempts last night and it seemed like their health WOULD NOT BUDGE, idk if this is just because only I was on them (Although I thought Relm said he was going to DPS them as well). Granted if we have a Mage dps them, we'll lose our DPS on LK, which I why I would put DoTs on them, then turn back to the LK so I could spam Shadow Bolt and refresh DoTs as needed. But regardless of however we do decide to do it, we have to get those Shamblings down before Phase 2 (Running to the edge)...or at very least have ONE up with low health.
Also remember, not every stratgey is going to suit our needs. Granted there's videos out there and people who have done this in the past, but what worked for them, may not necessarily work for us and what we have at our disposal. Just something to keep in the back our head, since this is obviously one of the more in-depths raid-awareness fights we've seen so far in ICC. Overall I think we did great for one, having never been there before and two, for not really knowing the fight, a few were kinda reviewing the fight inbetween wipes and afks. I mean think about it, a few times (granted not everyone was alive, but most still were) we actually made it INTO Phase 3 (The start of the Valks and Defile aka void zone, black shit, cloud o death, 50 DKP Minus). Which in my eyes, is only a precurser to come...also not sure if everyone knows this...but from what I've taken from the videos...we only have to get him to 10%...then it's a free kill.
Part 1
Part 2
I understand...
I'm not at all trying to push a stradegy on you, I certainly understand you'll have to develop your own concepts in certain cases, there are only suggestions from my experience.
The shamblings don't regenerate, but they have a rediculous amount of health, it would take the entire raids focus to kill them w/o the plaque ticks, dots will be useless, compared to the value of the plaque damage once the stacks are up. The shamblings weren't 1 shots on our tanks enraged in 25, so they shouldn't be in 10. The only time our OT's died to enrages was when both were enraged at the same time. We worked around this by using a hunter rotation but that was in 25 w/ 2 hunters. You won't have that most likely. A rogue can handle it for 2, but it adds another risk that the dispelled plaque will jump to the rogue instead of an add, but a quick healer can deal w/ that too.
As I said the trick is getting the plaque stacked high, but this will also kill the 3rd shambling before the 4th one, so the 4th one will wipe you most likely.
yeah
I see the Shamblings like the oozes in Putricide. You need to transition to phase 2 without one up, or if one is up, he needs to the plague on it, or you're fucked. We need to time the dps to transition out of phase 1 so that we don't have 1 or 2 Shamblings up, or one without a plauge or it's a wipe.
It's all good
I think we had phase 1 pretty much down last night. Each phase and transition we can get down and then it'll all come together. I think next time we get on him we'll spend more time in phase 3.
We first need to figure out how to do phase 2 properly and get out of that phase 2 transition into phase 3 with people alive. Last night at first we couldn't get into phase 2, then we were getting into phase 2 with a couple people alive, then we were allg etting into phase 2 and not getting to phase 3, and by the end of the night we were getting into phase 3 with a couple people alive...Not bad for the first nights attempts.
Let's focus on the 1st through 3rd phases in our learning at this point. don't ignore the other ones, but lets focus on mastering those first.
Right
The plague thing we still have to master, from everything I've read thats the key into knocking down the Shamblings. Phase or 1.5 lol, didnt seem so bad, the snowballs as simple to deal with, they have only 6k health two dots were taking care of those. The spirits on the other hand we have to work on, is there any order in which we take them down?
In Order
Just focus them down in the order they spawn.