Hero of Shattrath

If you are Aldor exalted you can hand in Dampscale Basilisk Eye for the quest More Basilisk Eyes to grind to Scryer neutral, allowing you to then hand in Scryer rep items. For Scryer to Aldor, you would hand in Dreadfang Venom Sac for the quest More Venom Sacs, followed by Aldor rep items.

LoKHor

You should get the title 'Hero of Shattrath" for earning this achievement, because it would be such a rare title :D

This Feat of Strength is relatively easy to complete--just time consuming.

Aldor / Scryers Reputation:
Hated - Neutral: Dreadfang Venom Sac / Dampscale Basilisk Eye x1344 (x1224 Human)
Neutral - Honored: Mark of Kil'Jaeden / Firewing Signet x360 (x328 Human)
Honored - Exalted: Mark of Sargeras / Sunfury Signet x1320 (x1200 Human)
Honored - Exalted: Fel Armament / Arcane Tome x95 (x86 Human)*

*Arcane Tomes and Fel Armaments are turned in one-by-one and give 350 Reputation each, though are usually more rare (and expensive) than Marks and Signets.

I personally went from Scryers to Aldor. The Venom Sacs are easily farmed from spiders West and South of Allerian Stronghold in Terokkar Forest. The Marks of Kil'Jaeden are farmed from NPCs within Shadow Tomb in North-West Bone Wastes of Terokkar Forest. The Marks of Sargeras are relatively easily farmed from trash mobs within Shadow Labyrinth.

These numbers assume no additional quests are completed once Neutral status is attained. You can gain approximately 4,075 (4,482 Human) reputation re-doing the Netherstorm Manaforge Quests--I found farming the marks more time efficient; though some classes might find the quests easier. Good luck completing!