Need help for Emotion Commotion.

I am completely lost as to what to do. I'm at the part where you need to retrieve 2 elemental clusters from oc serve. I looked on the wiki, and the types that drop the item are found in Soith Hardheart canyon. However, the wiki does not say what part I need to destroy. Further more, before I manage to kill them, a strong enemy will start attacking me, killing me quickly. When I do manage to kill them, I don't get the item, no matter which appendage I destroy. I tried looking in other areas, but I could not find any. A little help?