If you already have Ghoulbane he will offer both of these quests. Only one subquest is needed to complete the HQ, but if you wish to do both subquests, ask about Ghoulbane and accept that quest, then speak to Hack again and ask about a powerful weapon.
Evil-aligned characters at level 66 or better can walk through any Qeynos gate to get to Toranim if they are doing Ghoulbane Empowered. Only the two level 95 epics(x3) on the palace drawbridge in North Qeynos will be agro.
Kill Mordiggian, 68^^^ Heroic mob in the The Breathless Hollow of Loping Plains. To spawn him click twice on a plate on a rock near Freethinker Hideout ( -380, -13, 141 ) /waypoint -380, -13, 141. He will have 3 waves of adds. When the adds pop, he depops and respawns back at the plate. The adds are a separate encounter.