Here is a guide to the Huntsman Altimor fight in Castle Nathria on Normal and Heroic difficulty.
First of, on N O R M A L :
Huntsman Altimor has a dog he uses for battle, thus you are going to fight him along with the dog one at a time. After you kill the first dog, the second dog will appear and later the third one. One tank on Altimor and one tank on the current dog. Any damage you do to the current dog is copied to the boss and vice versa. When Altimor runs out of dogs, he takes way more damage so DPS priority on the dog.
Altimor does two things throughout the battle. Spread Shot is a wide cone aimed at someone which does instant damage. If everyone is spread out around the boss, less chances for the boss to hit players. Sinseeker will mark a couple of players then do damage in a line to each one and only the targets will get hit. Either move with that to avoid slicing up clumps of melee or everyone else can sidestep you but remember to always stick to the plan. Indecisive movements end lives.
Margore will be the first gargon to fight. His jagged claws is a stacking bleed on the tank, and you can tank swap to drop that once it starts to hurt. Vicious Lunge will pick somebody and and do a shared AOE on them. Others should stack on the target to help soak. If you get this and you have a good immunity (ex: ice block) or you can soak alone, remember to let others know to prevent mishaps.
After Margore is Barghast. He will spawn Shades of Barghast adds that spam raid damage while they’re up. You can CC them and each CC you use makes them take increasingly more damage. After a couple of minutes, they become immune to CC so you must finish the job as soon as possible. Submerge them on CC and kill them immediately. Remember that they are beasts so do not forget your hibernates and scare beast along with your usual stuns and fears. Bartimus will also target his tank with Rip Soul which spawns a friendly add that needs to be healed to full before it reaches Altimor. The starting health of the add depends on how healthy the tank was when Rip Soul went out. Before the cast, you can prepare by topping up the Barghast tank and having them get some distance from Altimor to buy the healers time. Healing the add is a top priority. Do not let the boss eat the soul.
After Barghast dies, next up is Hecutis. Each of his melee attacks will give him a stack of crushing stone which makes him hit harder and slows his movement speed. The tank can drop those stacks by moving him although doing that causes raid damage. You are going to cycle between standing and dragging depending on whether the tank or the raid is in more danger. Hecutis will also debuff a couple of people with a petrifying howl. Targets will get a big ring on them, which will make them slower and then they will drop a big old puddle. If you get that, run out to drop it on the edge quickly else you will be too slow to get rid of it.
On H E R O I C :
Couple of upgrades are present on Heroic. Rip Souls will cause raid damage while they are active and Margore’s vicious lunge soak attack will also start to apply a bleed, meaning you would want to soak it with as few people as can safely do it. You should not need more than three or four.
Video chapters:
0:00 – Basics
0:31 – Huntsman Altimor
0:59 – Margore
1:27 – Bargast
2:18 – Hecutis
2:57 – Heroic Mechanics