My monk is 898 ilvl and I crushed the WW challenge in 3 attempts, but to be fair I had about 10 practice attempts doing it a couple of weeks ago for my main's alt spec (Disc Priest does the same challenge). Honestly, if you know your class at all, the Feltotem challenge is by far the easiest of all of them.
Here is my monk, using the challenge appearance as proof:
https://worldofwarcraft.com/en-us/ch...age/synchordia
Ignore the wurm in the first phase. Its sonic screech doesn't even lock you, unless you get caught casting an effusion for health when it goes off, like I did once. But you can still attack with everything except chi wave if that happens. Note that Chi Wave, healing elixir, and the single piece of 652 leech gear on my WW was more than enough self-healing for P1.
Use Whirling Dragon Punch over Serenity to kill the eggs quickly; that and FoF will melt the adds through the incidental AoE. Keep Tugar in the middle of the room, near the fire/cauldron and
never untarget him unless you're killing the stun totem. Your interrupt should be available every time he tries to Fel Burst you, but just in case, every time leg sweep is available use that instead to reset the lineup. If you eat a Fel Burst, you pretty much die unless you have a 925-930+ ilvl because it hits for over 3M. If you get hit with the charge, there's a good chance you'll die to a Fel Burst, so don't. Kite around, always making sure you put the fallen rock between you and the underground wurm. Destruction Warlocks also do this challenge, and if you fear Tugar as he casts earthquake, the adds don't spawn. You could try leg sweeping him, that might have the same effect. This challenge isn't about the DPS, but instead it's all about iron-willed execution during phase 1. The underground earthquake phase lasts until the wurm hits all three rocks.
After Tugar dies, the wurm deals 150% more damage, and its sonic screech starts stacking increasing damage. It can be stunned with leg sweep to buy you some time. Try to line up cooldowns with Touch of Death - delaying a FoF of Strike of the Windlord a couple of seconds to make ToD do more damage is probably a good idea. Use Touch of Karma on the screech, it should absorb almost all of it, even a late one when the wurm is close to death, and reflect all of it back. You'll also for a couple of very late ones cast a couple of Effusions to get back up your HP - if you're not at about 80%+ you'll probably die if you're 2-3 minutes in. But seriously, once Tugar is dead you're pretty much home free. I've only wiped on phase 2 on this challenge once ever with a character, and that when when dumbass me locked myself out of holy spells on my Priest.
I also have no idea for the BrM challenge because I've never done the tank one (all tanks do the same challenge). I have heard it's miserable, and that was a bear druid who told me that. Since they're pretty much a raid boss in terms of difficulty to kill, I presume it's obnoxiously difficult for the other tanks.