Arathi Basin Battelground appears in phase 4.
The The Defilers is Horde faction for Arathi Basin battleground.
The reputation gives you access to following items:
Friendly-Reputation Items
Superior Healing Draught; 5 
(x5); Mid-level HP potion. Can only be used within PvP battlegrounds.
Superior Mana Draught; 5 (x5); Mid-level Mana potion. Can only be used within PvP battlegrounds.
Defiler’s Field Ration; 10 (x5); Low-level HP and Mana food. Can only be used in Arathi Basin.
Defiler’s Iron Ration; 15 (x5); Mid-level HP and Mana food. Can only be used in Arathi Basin.
Defiler’s Enriched Ration; 20 (x5); High-level HP and Mana food. Can only be used in Arathi Basin.
Defiler’s Silk Bandage; 10 (x5); Low-level bandage. Requires 125 First Aid to use. Can only be used in Arathi Basin.
Defiler’s Mageweave Bandage; 15 (x5); Mid-level bandage. Requires 175 First Aid to use. Can only be used in Arathi Basin.
Defiler’s Runecloth Bandage; 20 (x5); High-level bandage. Requires 225 First Aid to use. Can only be used in Arathi Basin.
Defiler’s Talisman; 4 
12 ; Trinket with an absorption on-use effect.
Honored-Reputation Items
Defiler’s Cloth Girdle; 5 36 ; Intellect Cloth belt with Spell Critical Strike chance and Spell Power.- Defiler’s Leather Girdle; 6 65 ; Stamina Leather belt with Critical Strike Chance and AP.
- Defiler’s Lizardhide Girdle; 6 67 ; Intellect Leather belt with Critical Strike chance.
Defiler’s Chain Girdle; 7 54 ; Stamina Mail belt with Critical Strike chance and AP.- Defiler’s Mail Girdle; 7 89 ; Intellect Mail belt with Critical Strike chance.
Defiler’s Plate Girdle; 5 10 ; Strength Plate belt with Critical Strike chance.
Revered-Reputation Items
Defiler’s Cloth Boots; 7 46 ; Intellect Cloth boots with Movement Speed and Spell Power.
Defiler’s Leather Boots; 9 25 ; Agility Leather boots with +Movement Speed and AP.
Defiler’s Lizardhide Boots; 9 29 ; Agility/Intellect Leather boots with Movement Speed and AP.
Defiler’s Chain Greaves; 11 54 ; Agility/Intellect Mail boots with Movement Speed.- Defiler’s Mail Greaves; 11 54 ; Agility/Intellect Mail belt with Movement Speed.
Defiler’s Plate Greaves; 8 6 ; Strength/Agility Plate boots with Movement Speed.
Exalted-Reputation Items
Defiler’s Epaulets; 11 56 ; Intellect Cloth shoulders with Spell Power and MP5.- Defiler’s Leather Shoulders; 14 35 ; Agility Leather shoulders with AP.
- Defiler’s Lizardhide Shoulders; 14 40 ; Intellect/Agility Leather shoulders with AP.
Defiler’s Chain Pauldrons; 17 68 ; Agility/Intellect Mail shoulders.
Defiler’s Mail Pauldrons; 17 99 ; Intellect/Strength/Agility Mail shoulders with MP5.- Defiler’s Plate Spaulders; 11 9 ; Strength/Agility Plate shoulders.
Deathguard’s Cloak; 11 85 ; Agility Cloak with AP.
Ironbark Staff; 45 41 ; Intellect Staff with Critical Strike chance and Spell Power.
Mindfang; 38 54 ; Intellect Dagger with Critical Strike Chance and Spell Power.
How to Gain Reputation
- Quests
The Battle for Arathi Basin!: Available at Neutral, awards 500 Reputation with The Defilers.
Take Four Bases: Available at Friendly, grants 800 Reputation with The Defilers.
Take Five Bases + 500 reputation + 
Battle Tabard of the Defilers
- Marks of Honor
Turning in 3 
Arathi Basin Mark of Honor grants 50 Reputation with The Defilers.
You gain 3 Arathi Basin Mark of Honor when you win Arathi Basin game, and 1 for losing.
The quest For Great Honor, which requires 3 Marks of Honor from both Arathi Basin, Warsong Gulch and Alterac Valley grants 150 Reputation. This quest is repeatable, but subsequent turn-ins grant 100 Reputation.
- Battleground Honor
Each 200 resources you obtain during battle grant you 10 Reputation and 100 Reputation if you win the battleground.
During Arathi Basin Battleground Weekends, you will gain 10 Reputation for every 150 resources, for a total of 130 Reputation if you win the battleground.
