The Scryers are blood elves who reside in Shattrath City led by Voren'thal the Seer. The group broke away from Kael'thas Sunstrider and offered to assist the Naaru at Shattrath City. They are at odds with the The Aldor, and compete with them for power within Shattrath and the Naaru's favor.
Most players will start at neutral with the Aldor. Khadgar in Shattrath City will give players the choice of aligning themselves with the Scryers or Aldor after completing City of Light. This choice is reversible if players feel the need. Blood elf players will be friendly with the Scryers and hostile with the Aldor, whereas draenei players will be hostile to the Scryers and friendly to the Aldor.
The Scryers have both a Enchantress Volali trainer and a High Enchanter Bardolan trainer. Due to this, the enchanter nestled deep within Uldaman is rendered obsolete.
Quartermaster Enuril and Scribe Veredis are located in the Scryers bank on the southern edge of the Terrace of Light. The Seer's Library in the Scryer's Tier is home to Arodis Sunblade <Keeper of Sha'tari Artifacts> and Veynna Dawnstar <Keeper of Sha'tari Heirlooms>, who exchange epic armor tokens for Tier 4 and Tier 5 gear, respectively.
Note: Reputation gains with Scryers correspond with a 10% greater loss of reputation with the Aldor. Most reputation gains with the Scryers will also grant 50% of the reputation gained toward your standing with the The Sha'tar.

Lore

After enduring relentless assaults, the harried Sha'tar and Aldor guards braced for the next wave as it marched over the horizon. This time, the attack came from the armies of Illidan Stormrage. A large regiment of blood elves had been sent by Illidan’s ally, Prince Kael'thas Sunstrider, to lay waste to the city. As the regiment of blood elves crossed the bridge, the Aldor’s exarches and vindicators lined up to defend the Terrace of Light. Then the unexpected happened, the blood elves laid down their weapons in front of the city's defenders. Their leader, a blood elf elder known as Voren’thal, stormed into the Terrace of Light and demanded to speak to the naaru A'dal. As the naaru approached him, Voren’thal knelt and uttered the following words: "I’ve seen you in a vision, naaru. My race’s only hope for survival lies with you. My followers and I are here to serve you."
The defection of Voren’thal and his followers was the largest loss ever incurred by Kael’thas’ forces. Many of the strongest and brightest amongst Kael’thas’ scholars and magisters had been swayed by Voren’thal's influence. The naaru accepted the defectors who became known as the Scryers.

Reputation

Until Honored
Players looking to gain the higher reputation ranks (revered, exalted) may wish to save non-repeatable quests until after reaching honored.
Turning in 10 Firewing Signet to Magistrix Fyalenn in Scryer's Tier will grant 250 reputation with the Scryers. These signets can also be turned in one at a time at the same exchange rate, 25 reputation per signet. These signets drop from low ranking Firewing members found in the northeast section of Terrokar Forest. This repeatable quest becomes unavailable at honored. If no other reputation quests are done, 240 signets are required to go from friendly to honored.
Until Exalted
Once you reach level 68, you may also turn in Sunfury Signet. These drop from high-ranking Sunfury blood elves (found in Netherstorm, Shadowmoon Valley, and the Tempest Keep instances). If you wish, you may turn in the higher level signets before honored reputation, however it is recommended that you save them for after you hit honored. For every 10 signets, you will gain 250 reputation. Once you hit honored it will take approximately 1,320 Sunfury signets to go from honored to exalted if no other reputation is earned.
Arcane Tomes
Arcane Tome may be turned in at any time to Voren'thal the Seer inside the The Seer's Library on the Scryer's Tier. This will increase your reputation with the Scryers by 350 per hand-in. If you wish, you may turn in the Arcane Tomes before honored reputation, however it is recommended that you save them for after you hit honored. Once you hit honored it will take approximately 94 Arcane Tomes to go from honored to exalted if no other reputation is earned. In addition to reputation gains, you will receive an Arcane Rune, which is currency for the purchase of shoulder enchants from Inscriber Veredis, who resides in the Scryers bank.

Switching to Scryers

To change your faction from Aldor to Scryers to access their crafting recipes (and undo all reputation progress you have made), find Arcanist Adyria, a Scryers in the Lower City. She offers you a repeatable quest, Voren'thal's Visions, that requires you to find eight Dampscale Basilisk Eye. Once you are Neutral with the Scryers, you can no longer receive this quest. The quest gives you +250 Scryers reputation and -275 Aldor reputation (in addition, the quest also gives you +125 reputation with The Sha'tar).