World of Warcraft/Blood for Blood

Region: Hellfire Peninsula
Questgiver: Magistrix Seyla at the Throne of Kil'jaeden
Objective: Magistrx Seyla at the Throne of Kil'jaeden wants you to kill 4 Emaciated Felbloods by using the Fel Siphon on them. You will need Demonic Blood from nearby Wrath Heralds to power the Fel Siphon.
Reward: 11 gold 99 sliver and choice of 5 Marks of Sargeras or 5 Sunfury Signets.
Rep: +275 with the Shattered Sun Offensive

The Throne of Kil'jaeden is only reachable via flying mount or by the teleporter on the Sunwell Isle.

This daily quest was added in patch 2.4.

Magistrix Seyla also gives the quest Blast the Gateway.