Onyx Hearts

Onyx Stormclaws can be pulled without the Serpentbinders, who are always at their side.
Just engage the group with your flying mount. If you stay a little bit above the ground, the Stormclaw will attack and follow you, whereas the Serpentbinder will ignore you. Draw the Stormclaw a bit away, dismount and kill it. You can also easily pull multiple Stormclaws this way.

Since the Stormclaws are fairly weak and you don't have to kill the Serpentbinders now, you'll finish this rather annoying quest in no time.

The quest items drop from the Onyx Stormclaw that accompany the Shan'ze Serpentsbinders.

I found the fastest way was to go to around 24,10, the north western part of the island, where a lot of them are somewhat gathered.

This has to be one of the most horrible dailies. I'm getting a drop rate of around 5%, 30 mins of grinding now between the third and fourth heart :S at least the flying pulls make it a little quicker compared to when i started and was killing both enemies.