This fight doesn’t have a whole lot of rogue-specific aspects. If you position yourself well, You should have opportunity to get a good rotation going during the first phase of the fight.
First – make sure you are never in front of the boss, even for a moment. His Saber Lash hits once per second, and if you’re near the tank it will take you out instantly.
His hit box is enormous. When the tanks have him positioned you will get behind him, of course. You want to stand actually slightly inside his hit box, because his coldflame only spwns outside the hit box. The healers should stand very cloe to you.
Phase 1 is fairly simple. The tanks pick him up and keep him faced away from the raid so that they soak up the Saber Lashes. YOu stand behind him and get your rotation going. While Rupture-less rotations are the rage now, you are going to do some target switching, so its not a bad idea to have a bleed on him to keep ticking while you change targets.
He will create Coldflame, which are blue fires on the ground that spread out in lines from him. You can easily avoid those. If your health is low and you find yourself having to cross a line of flame, you can CoS to avoid the damage.
When he casts Bone Spike Graveyard, someone in the raid will get impaled on a spike from the round. The spike needs to be attacked, and it will die quickly. That’s why you want the healers to be near you – if they get spiked you can quicly turn and take out the spike without wasting time running.
This goes on for 30 seconds. Then phase 2 begins. Marrowgar will start whirlwinding (called Bone Storm). If you’re like me, you still have bad dreams of whirlwinds one-shotting you. That won’t happen here. The damage from his spinning attack is not too bad. If your health is low already, try to run to the other side of the room, because the whirlwind damage is reduced with distance, but you cannot avoid the damage while he moves around the room. Evasion will help you avoid some of the damage if its available, but Feint works as well, so make sure to use them and help your healers out.
Three times during his whirlwind Marrowgar will stop and send out lines of coldflame. You need to watch for these and avoid them. They travel out in an X from his stopping location.
If your healers are not having any trouble during the Bone Storm, then feel free to keep dpsing him. Make sure to stop when he goes to his third target so that the tanks can get aggro in the transition back to phase 1.
Be careful while you’re running around to avoid the coldflames. Don’t end up near the tank. Once the Bone Storm ends, the tanks will pick him back up and the Saber Lashes start. If you’re near the tank when the first Saber Lash hits, then you’re gonna die!
When the tanks have him, its back to phase 1 and get your dps rotation going again. Group near the healers for quick spike removal, and repeat. Remember to use Tricks of the Trade on the tank as phase 1 starts again because there is a threat reset.
Lord Marrowgar has a couple of nice rogue pieces. On 10-man normal mode, if you’re still running combat spec, you might like his axe – Bone Warden’s Splitter. All the agility-based dps will be rolling on the Shawl of Nerubian Silk.