A long snake fight about freeing trapped teammates and respecting lightning on the floor: A Knot of Snakes removes a player from the fight until the group breaks them out, and the Burrow charge one-shots and stuns anyone in its path on high keys. Hatch waves add a double-health Storm Serpent that must die first, and the Serpentstorm channel is the raw heal-check that ends undergeared healers.
Snakes wrap around a player, preventing all action and suffocating them for Physical damage every second; destroying or incapacitating the knot frees the victim and the clump unravels into snakes that attack.
Break the knot instantly with focused damage or an AoE stun, then have the tank gather the freed snakes so they die to cleave.
Merektha spits volatile energy at players, calling lightning strikes on their location every second for 4 seconds, and each strike leaves a Lingering Storm pool behind.
Targeted players run away from the group and drop the strikes along the wall so the melee space stays clean.
Pools of electricity left by Thunder Spit deal heavy Nature damage every second to anyone standing inside them.
Treat every pool as lethal ground and keep repositioning the group toward the clean side of the chamber.
Merektha burrows through the ground toward players, dealing heavy Nature damage, knocking up, and stunning anyone in her path for 4 seconds, while Burrowquake pulses damage on the whole group.
Sidestep the burrow line immediately and keep moving while she is underground; getting clipped on a high key is a death plus a 4 second stun.
Merektha sinks her fangs into the tank for very heavy Physical damage plus a Nature damage-over-time effect lasting 7 seconds.
The tank uses active mitigation on every cast and the healer keeps healing through the 7 second bleed-style ticks afterward.
Eggs around the chamber hatch waves of snakes that attack players, including a Storm Serpent with twice the health of the regular Toxic Vipers.
Group the hatched snakes on the boss and cleave the Storm Serpent down first before returning to single-target.
Merektha exhales, knocking back the whole group and applying a Nature damage-over-time effect for 8 seconds while Storm Strikes hammer locations across the chamber.
The healer commits a major cooldown to the channel while everyone dodges the Storm Strike impacts and holds a personal for the DoT.
Mitigate every Lightning Bite, and stack the snakes freed from each A Knot of Snakes so the group can cleave them down.
Plan major cooldowns for Serpentstorm, pre-top the Lightning Bite target, and remember the bite keeps ticking for 7 seconds after the hit.
Own the knot: break it instantly when it grabs someone, then swap to the Storm Serpent during each Hatch wave.
Watch the ground while Merektha burrows and never fight inside old Lingering Storm pools.
Tyrannical: Lightning Bite plus its ticking Nature damage will nearly kill an unmitigated tank, and Serpentstorm overlapping Storm Strikes becomes the hardest healing wall in the dungeon, so hold Bloodlust or defensive rotations for those windows rather than the opener.
Sources: Icy Veins - Temple of Sethraliss Dungeon Guide (updated for Season 2, Aug 11 2026) · Wowhead - Temple of Sethraliss Season 2 M+ overview · Wowhead - Temple of Sethraliss Mythic+ Route Guide · Wowhead - Adderis encounter journal NPC page (Season 2 ability data) · Warcraft Wiki - Temple of Sethraliss
