Beth’tilac is the spider boss of Firelands. Not necessarily a hard boss and I would even choose to attempt this one before Ryolith or Shannox .
Phase 1 and notice the packs of spiderlings, small spiders. Their whole purpose in life is to reach the bigger spiders, the drones. The drones hit for a lot and they get buffed with each small spider that reaches them. If too many reach the drone then it will kill your tank. Your main goal for phase 1 is to kill all the small spiders before they reach the drones.
To do this your 1st priority is to identify and mark the spawn locations of the spiderling and of the drones. This is how the encounter area should look before you start. You want to have the longest distance between the spawn locations and the area in which you tank the drones.
Assign trap locations and earthbind locations across these lines to slow the spinderlings.
Kill the spinderlings, kill the drones. Have 2 ranged assigned to killing the 3rd type of add, called Spinners, they are medium sized. These ones hang from above and don’t melee for much but do raid damage. If taunted they come down and can be meleed. What’s important is that they leave a line which if clicked on will allow you to climb up to the boss.
At the begging of the fight have your main tank 1st to climb. You need someone to climb up to Beth and engage her otherwise she will do a nasty raid wide attack. Two healers and some dps should follow your tank. The situation above is not that complicated, just engage her and try to put as much damage in as possible. Fire meteors will fall, don’t stay in those.
When Beth runs out of energy she will come close to the center to do Smoldering Devastion. A mass aoe ability that kills everyone above. Jump down through the whole in the center to avoid it. While down try to help the below team as much as you can, then start looking for opportunities to go back up again. It is important for the tank and healer to go back up as quickly and as synchronized as possible.
Beth will do her mass aoe 3 times and then she will come down completely to begin phase 2 of the fight. Phase 2 is a burn out phase , you only fight Beth, no more adds but your main focus should be on her frezy buff stacks. She gains one every 5 seconds and they act like a soft enrage timer, the more she gets, the harder she hits, at around 20 stacks it becomes problematic, and more than 30 will start killing you.
To kill her before she gains too many stacks you need to put some damage into her while she is above. If she starts phase 2 at 80% or below then you should be fine. We had only two dps above me and a dk, but some guilds used more.
What’s important is that when phase 2 begins, when Beth comes down… she will eat any remaining small spiders and this will give her health back. You really want to avoid this and one way to do it is not to send a dps team back up the 3rd time. The extra dps below would ensure a clear room when she lands.
Proper defensive cooldown rotation can be really powerful,. For example, on one attempt she completely healed up when she came down but because of good cooldowns we got her to 10% and this is with a raid in which very few ppl have heroic pieces of gear. I imagine that in the future when gear lvl will increase ppl. won’t even need to go up on the web to dps her.
Anyways cooldown management, how to do it, and this is not only for this battle, this will help you in the future also. Step one: identify by name the ppl in your raid that have cooldowns. These are holy paladins, prot paladins, warriors, shamans, druids for tranquility. You can ask them to come forth and say what cooldowns they have if you don’t know them all.
Step two make a list, any raider that wants to help out can do this, doesn’t have to be the leader. The list should be like 18 stacks on boss paladin1 uses aura mastery, start with aura mastery cus that’s weaker, 20 stacks paladin2 uses, 22 stacks druid, 24 stacks warrior1, 26 shamy totem, 28 prot paladin cooldown and so on. Make sure every player knows at what stack is his turn to use and you should be fine. The cooldowns last 6 to 10 seconds, the boss gains a stack every 5 seconds but even with some gaps you should survive.