Experiments require resources. Thorngrin the Tender makes sure that Kael'thas's botanists have the power and essence they need to reveal the naaru's secrets, even if that means untold numbers of living creatures must be sacrificed to obtain it.
- Sacrifice — Thorngrin the Tender teleports a player to his platform, stunning them and leeching health from them, inflicting Shadow damage every second for 8 sec.
- Hellfire — Thorngrin the Tender ignites the area surrounding him, causing Fire damage to himself and all players within 0 yards of him every second for 6 sec.
- Enrage — Thorngrin the Tender enrages, increasing his attack speed by 75% and his Physical damage dealt by 75% for 10 sec.
Before engaging Thorngrin, his room must be cleared. There are two pulls of four demons and a Channeler; although it seems like they pull together, you can actually pull the demons separately if you wait until the Channeler walks forward towards Thorngrin (just wait until the buff wears off of them, or you'll be in a world of hurt.)
There are also two stealthed satyrs who patrol in the next room (as you go towards Laj). They should be killed before fighting Thorngrin, as you can easily aggro them by mistake if they have patrolled close to the boss.
- To keep healers out of LOS, place the tank in the middle of the room, and put the healer behind the boxes to the left of Thorngrin's starting position. The healer should be able to see the tank, but will not be in LoS of the boss. With a single healer this may help, since then (in theory) they will never be sacrificed. With multiple healers (even if one is not specced for it) this is rarely a problem.
- Thorngrin is normally tanked in the middle of the room; healers (if not trying to stay out of LOS) should stand between Thorngrin and the raised platform where Sacrifice victims go. This way the healers can reach all party members (if you stand on the other side, Sacrificed members may be out of healing range). Ranged DPS can simply stand on the sides of the room.
- Because Hellfire and Sacrifice both mess up melee DPS, ranged DPS makes the fight substantially easier. However, it is very doable with heavy melee DPS as long as they can avoid taking too much damage during Hellfire casts.
- Hunters: (As of 09/05/08) On normal and heroic mode, Thorngrin is not immune to viper sting for mana draining. As you can imagine, this makes the fight immensely, immensely easier.
- Aggro can be a problem if your tank does not have enough HP/FR (or your healer does not have enough mana) for the tank to keep meleeing during Hellfire casts. If this is the case, you may need to taunt after he casts Hellfire, or have your ranged DPS not attack while he channels.
- Greater/Major Fire Protection Potions can be helpful for the tank if they intend to stay in for Hellfires. If you drink one and then start the fight when it has about 1m left on its timer, you should have the potion cooldown up in time for the second or third Hellfire.
- Around 250 FR should be enough to let the tank easily stay in during Hellfire, even without extremely good healing. However, be careful not to sacrifice too much Defense/Armor, since Thorngrin hits * extremely* hard during his Enrage phase. Therefore, running out of Hellfire is prefered over staying in it with fire resist gear.
- Another tactic for dealing with Enrage is to kite him—Mages can Iceblock, or a Hunter can FD when he gets close. However, pulling aggro at the right time can be tricky.
- Apparently, the snakes from a Hunter's Snake Trap can be hit by Sacrifice. Releasing the trap at the right time may enable you to avoid it most of the time (unverified as of patch 2.2.0).
- Warlocks can use Enslave Demon on one of the elite Satyrs in Thorngrin's room, and then use that mob against Thorngrin. These demons deal extremely high damage and can make the fight much easier. This technique is usable in several of the boss fights in Botanica if you move quickly. Note however that in heroic mode they are immune to enslave.
Alternate LOS Strategy
The goal of this strategy is to keep everyone in the party out of line of sight, so that Thorngrin never uses his Sacrifice. Tank should wear DPS and fire resist gear, hybrid classes should go heal mode. Rogues can take a nap. The party stands in the hallway outside the demons' room. The tank pulls Thorngrin up the ramp, positioning him just outside of line of sight, west of the doorway. The tank stands in the doorway, in line of sight of healers. Tank supplies almost all the DPS on this fight; ranged AoE classes can drop AoE in the doorway and hit Thorngrin with it. Just heal through the Hellfires and Enrages.
If the positioning is right, Thorngrin will occasionally turn to party members and try to cast Sacrifice, but will never be able to.
Straight Tanking (Heroic)
This method works best with 3 ranged DPS. Tank the boss in the middle of the room so his AoE is out of the range of the first step of the stairs where the boss spawned. Have your DPS and healer standing on the step. During the fight the tank need to watch when the boss randomly chooses a party member to Sacrifice. After the sacrifice is started, the boss will randomly aggro on another DPS/healer; that is when the tank needs to use the taunt ability to bring the boss back to the middle of the room before he does his AoE (the tank stays inside the AoE). If the taunt is a bit late, DPS can move back up the boss' stairs a bit to avoid the AoE. Resume original position after AoE. Sacrifice is not a big problem with this method, but requires the tank to be precise on when to use his taunt.
- Welcome my brothers! Bask in the glory of my power!
- What aggravation is this? You will die!
- Scream while you burn!
- I'll incinerate you!
- I revel in your pain!
- You seek a prize, eh? How about death?
- Your life will be mine!
- Killing a player
- I hate to say I told you so...
- You won't... get far.