Stonespine

The Gauntlet
Enter from the service entrance or return from the Scarlet branch, then work through Anastari's, Nerub'enkan's and Maleki's ziggurats. After each boss, enter its building and clear the Thuzadin Acolytes; leaving them alive keeps the route to Slaughter Square shut. Deal with Magistrate Barthilas before the square if the service-entrance approach sent the magistrate running. Black Guard Swordsmith is a plans detour by Anastari's ziggurat, and Stonespine is an optional patrol encounter rather than a gate requirement.
Stonespine
Elite UndeadStonespine is a rare gauntlet patrol whose Vicious Rend can carry damage into the next pull even after the gargoyle dies.
Abilities

Vicious Rend
Inflicts Physical damage to an enemy every 3 sec. for 15 seconds.
Vicious Rend continues dealing Physical damage after it is applied. Keep healing its victim after Stonespine dies and avoid adding a new pull while the bleed leaves that player vulnerable.
Tank- Wait for Stonespine to reach a cleared part of the gauntlet instead of chasing the patrol through other enemies. Do not immediately add another pack while Vicious Rend is still damaging its victim.
Healer- Continue healing Vicious Rend after the gargoyle falls. Restore the affected player's health before the group commits to the next ziggurat or street pull.
Damage- Pull the rare only when the tank can meet its patrol in cleared space. Finish Stonespine without tagging nearby enemies, then let the Rend victim recover before starting another fight.