Just tryed twilight realm tanking halion on 10 man normal mode. Wiped the raid 4 times, resulting in a elitest puggie leaving and leaving my guildies going another week w/otheir ruby sanctum kills. I looked at the video on tankspot and dont understand how to handle thos orbs rotating around the room that cut the whole raids in half. Tried to have people explain to me but still dont understand. Never been so confused about a encounter mechanic in my career. Can someone clear this mechanic for me?
Tanking Halion in the Twilight realm isn't at all as hard as it might seem at first. Firstly, where you tank the boss in P1 is important because the portal spawns exactly where is he is standing when P2 shifts. I always pull him straight from the instance entrance to either very back of the circular area or to the right. This way I'm in an optimal position to pick the boss in the twilight realm.
I favor tanking the boss to the right in P1, alas when I enter the Twilight realm, he will be facing towards the door and it is very easy and safe to pick him up, without subjecting the raid to the danger of being cleaved. From there, I keep him facing towards the entrance of the instance and wait for the orbs to circle. The orbs have a strict timer and always spawn in the same place. Zoom your camera out and watch the orb that goes behind the boss and imagine the trajectory of the beam. When the timer says only few seconds until Twilight Cutter, slightly tweak the boss so that the orb passes behind the boss and to his right side. The preliminary position is otherwise good, but maybe just needs a step or two.
The beam will then cut through the boss, missing you narrowly. Then just follow the beam as it moves. It takes a bit of practice but after a couple of attempts, I managed to get it right; so that I would be close enough to the beam but not get hit by it, as well as not move the boss from the middle. He has a fairly sizable hit box, but for me, it's easy to stand right on his claws, so that when I move I don't accidentally back away from the middle which usually leads to annoying complications.
When the beam disappears, stop moving. The Twilight Cutter's timer is just enough to let the orbs make a full circle and if you don't move at all, the beam should manifest exactly where it left off. Then just rinse and repeat. I will add our first 10-man kill vid, cause it shows the positions pretty nicely, though I wasn't as good as keeping close to the beams while moving at that point, so you see the boss a bit over the place in P2 & 3.
My guild actually just got our first kill about 15 minutes ago and I tanked the twilight realm... After two weeks of wipes, we 1 shot it this week; very rewarding to say the least.
What I do is have our P1 tank head straight from the entrance and face Halion toward the entrance during P1 while the raid attacks from Halion's left side (the main tanks right side). P1 is fairly straight forward, run out for Combustion, don't stand in flames, etc...
Once he hits 75% I jump in the portal first, the raid gives me a few seconds, and immediately run so that Halion is facing the direction the raid engaged from (facing where the enrage/conflegrate boss was), this way the raid can spawn in and not get cleaved/breathed on. Once everyone is in we pop Bloodlust/Heroism to get through P2 as quickly as possible and get him to 50%.
On to your question...
How I manage the orb is fairly simple, although it took me 2 wipes to get smooth with it. First, I turn auto-walk on (or turn auto-run off, whichever). You have 30 seconds before the first beam appears, so I keep him still for the majority of Bloodlust/Heroism enabling max DPS time. Let the orb pass until there is 7 or so seconds until the first beam will spawn, at which point you need to find the orbs. Usually when I look the orb is at my 10 o'clock position; this is prime positioning for me. With the orb in this position the beam will pass on my right side, splitting between myself and the raid, giving them max leeway (essentially they are chasing a beam instead of running away from one). Sometimes I have to turn auto-run on for a second because depending on how perfectly (or imperfectly) I rotate myself means the orbs and beam may get a bit too close for comfort.
P3 is actually easier than P2 because there are less people to get hit by the beam and at that point you should be in a rhythm. Keep focused, don't tunnel vision, and make sure you have someone calling out which side needs to slow/hasten their DPS.
But remember, 10 o'clock is where you want the orb to be and the beam will pass on your right side and give the raid ample room to maneuver.