Got bored one night and just decided to agro one of the 1.2 million peacekeepers back to the alliance shrine.
(Actually, the stupid guard had already followed me back half way across the map and I was like meh, just let the guards in our shrine finish her off)
Well it turns out, no NPC can damage her less than 980k health. Guards will spawn and attack her. She also does this AoE demoralizing roar that can agro other npcs in our shrine.
The result was guards following me back to the horde shrine when I lured her back.
Once I died, the alliance and horde guards/npcs wrecked havoc on each other stuck in a forever battle not able to damage one another.
TIPS
Can only be done with a well geared healer (The peacekeepers hit hard! 22k per hit. 50k crits. Stuns and casts mortal strike debuff on you)
I was a druid which is probably the best class to do it. I can cast faerie fire to keep aggro. Put hots on myself. Use blink and speed to run faster and gain more distance. (The guard will not drop agro if u use blink. Just remember to use faerie fire again when she's in range)
Should do this when there is no alliance around in ur shrine cause basically that's the only thing that can kill the peacekeeper. Idiots will not listen even when u say stop or announce it in the general chat. This one paladin taunted it trying to help and managed to lose half the NPCS following her.
When you lure the guard back to the original base, u must do it slowly for it to cast demoralizing roar to keep agro on the npcs attacking her. Don't run too fast.
Forgot to take screenshots, but if anyone would like to do the honors after testing it out, please post. Imma try it again tmr night when there's less people around.