The Phoenix Lords

From left: Baharroth, Fuegan, Jain Zar, Asurmen, Maugan Ra, Karandras.

The Phoenix Lords are the greatest warriors of the Eldar, second only to the Avatars of Kaela Mensha Khaine himself. They are the greatest and most ancient of all the Exarchs. They cannot truly die for even if their body is destroyed another Eldar will find and don their armour. Thereby his consciousness will be overtaken by the first, strongest, and dominant mind of the original wearer. Only the doomed Bards of Twilight know all the details of the Asuryata, the legend of the Phoenix Lords. This ancient epic tells the origins of the Phoenix Lords and also speaks of their future. It warns of the Rhana Dandra, the final apocalypse when all the Phoenix Lords and the Eldar will gather in a final battle against Chaos. Its ultimate validity is unclear, something shared with every prediction of the future or tale of the past. Nevertheless it seems to be the main source of knowledge about the Phoenix Lords.

(Sourced from Lexicanum)

The Phoenix Lords are indeed like demigods themselves, and they instill fear in their enemies' hearts as they lead their warriors into battle. Maugan Ra, the Harvester of Souls, will bring swift death with his shuriken cannon, the Maugetar; Baharroth, the Cry of the Wind, will fly upon his enemies with his Hawk's Talon blasting away; Fuegan, the Burning Lance, will annihilate all in his way with his Firepike and his Burning Axe; Jain Zar, the Storm of Silence, will slay her foes in an instant with her devastating weapons, the Zhai Morenn: the Blade of Destruction, and the Jainas Mor: the Silent Death (a throwing weapon); Karandras, the Shadow Hunter, who will stalk his prey and crush them swiftly; and finally Asurmen, the Hand of Asuryan, who leads the Phoenix Lords, as he is the founder of the first Aspect Shrine: the Dire Avengers.

All of them worthy foes with millenia of experience!