Eldorath Starbane

Eldorath Starbane is an Eldar Farseer of Alaitoc and an arrogant bastard even among the Eldar themselves. This is mostly shown in the huge defeat of his Warhost as a result of the Siege of the Tomb World Somonor sometime in M41.

The battle began in the Eldar's favour, though his prescience was muddled by a combination of Imotekh's tactical skill and Orikan the Diviner's own abilities. Doing an uncharacteristically (for a Farseer) careless rune reading, he foresaw victory after the retreat of Imotekh the Stormlord and pressed on deeper into the Necron catacombs under the planet's surface (not a very good idea), not realizing it was an obvious trap (or the obvious fact that the runes never said WHOSE victory it would be). After being sealed inside the tombs, with the only way out closed by the Quantum Shield, he was ambushed by Necron Scarabs and then Flayed Ones and finally Immortals who obliterated the grouped Eldar as they were trying to fight off the Flayed ones. Eventually, the only Eldar left standing was Starbane who was obviously thinking one word: OOPS. So then Imotekh had his right hand cut off as a sign of humiliation and let him get away to his Craftworld. Starbane has pledged vengeance against the Sautekh Dynasty ever since. Good times.

He then went off fighting some Orks in Rynn's world with the Crimson Fists but then sometime later he was defeated again by the Necron lord Anrakyr in the Carnac Campagin.

He seems to be something of a whipping boy for Matt Ward. He features in the White Dwarf battle report introducing the Necrons, in an army allied with the Ultramarines (despite the fact that the Imperium are supposed to be Alaitoc's main enemies, but that's Ward for you). The Eldar and Imperium barely win, but after the battle Trazyn captures Eldorath and gives him to the Ultramarines as a captive, most likely averting his planned vengeance against the Sautekh dynasty.

Older Than You Think

However, Eldorath Starbane was actually introduced in a story from the 3rd Edition Necron codex.

In the story, Eldorath is directing Alaitoc to try and locate the Imperium's training facility of Culexus assassins. This is because a Culexus killed his sister (also a Farseer) and the Eldar consider dying at the hands of one to be a horrific fate (complete destruction of the soul vs an eternity of torture at Slaanesh's hands). Once they're close to the headquarters, Eldorath is about to give the order for Alaitoc's forces to destroy it. However he remembers his Farseer training, though he's eager to avenge his sister, and reads the runes to see the future consequences of his descision; a good move, as every alternate future he sees where Culexus temple is destroyed gets Alaitoc practically destroyed as well by unidentified assailants (most likely Necrons or the Imperium). Eldorath is torn but (in a move unlike Ward's depiction), gradually swallows his pride and vengeance before calling off the attack. As Alaitoc retreats, the story concludes with a bitter Eldorath deducing that the Necrons and/or the C'tan put the pariah gene in humanity, likening it to sowing crops, and preparing to harvest them.

Matt Ward most likely took elements of this story when he wrote the 5th Edition codex, but as usual he changed several things, such as Eldorath's competentency. Whether you prefer the 3rd Ed or 5th Ed version, Eldorath is an enemy of the necrons and his story can be taken in whatever direction players desire in their battles.