Xathuux builds rage until Demonic Rage bursts the party, speeds his swings by 75 percent, and starts spreading Burning Steps pools from his feet, so the tank slowly kites him around the edge of the room. Keys die when the thrown Axe survives too long and its stacking Fel Lightning overwhelms the healer, or when Infernal Crush lands during the rage window with no defensives left.
At full rage Xathuux erupts, dealing Chaos damage to the whole party, gaining 75 percent attack speed, taking 30 percent increased damage, and gaining Burning Steps for 15 seconds.
Use personals for the eruption, then punish the window: he takes 30 percent extra damage while raging, so this is your burst phase.
Fel fire spreads across the ground from Xathuux's feet and the pools stay down for a long time, ticking heavily on anyone standing in them.
The tank kites the boss along the outer edge of the room during rage so the pools paint the perimeter instead of the party's space.
Xathuux hurls his axe at a random player's location for heavy Chaos damage, and the axe stays in the ground pulsing Fel Lightning until it is destroyed.
The targeted player brings the impact into melee range so the group can cleave boss and axe together; the axe dies first, every time.
While the axe is planted it channels beams at every player, ticking Chaos damage each second, and the effect stacks the longer the axe lives.
Treat the axe as a priority add; every extra global it survives is another stack ticking on all five players.
Xathuux slams the ground and energy erupts under targeted players, dealing a large Fire hit plus a Fire damage-over-time effect for 8 seconds.
Targeted players use a defensive before the impact, and the healer pre-loads healing since the DoT keeps ticking afterward.
A massive frontal axe swing on the tank that deals heavy Physical damage and reduces the tank's healing received by 80 percent for 8 seconds.
Tank covers every Legion Strike with active mitigation, because for the next 8 seconds the healer cannot meaningfully heal it back.
Mitigate every Legion Strike since the 80 percent healing cut means you must survive it yourself, keep the boss parked on the planted axe, and kite along the outer edge once Burning Steps starts.
Pre-cast before Infernal Crush lands, ramp during rage windows, and remember your tank is nearly unhealable for 8 seconds after each Legion Strike.
Kill the axe as the hard priority target, stay out of the boss frontal, and pour cooldowns into the 30 percent damage-taken window during Demonic Rage.
Never stand in Burning Steps pools, and hold a defensive for the Demonic Rage eruption.
Tyrannical: A Legion Strike taken without mitigation under the 80 percent healing reduction will kill the tank, and Fel Lightning stacks become lethal within a few seconds, so the axe kill priority is absolute and rage windows need pre-assigned personals.
Sources: Wowhead - Murder Row Dungeon Overview (Patch 12.1) · Warcraft Wiki - Murder Row (instance) · Icy Veins - Murder Row Dungeon Guide
