I ended up with a bunch of these invokers, and I click the others each time I see them, but I somehow only have one wrathful heart. Do these only spawn in certain dungeons? I have pretty much solely done NM dungeons to level and need a specific wrathful heart for my new spec. I did a google search on it, but the information was pretty vague.

U go to the seasonal malignant dungeons and there's a room at the end that let's you use invokers. Use said item and the mini boss drops whichever invoker you used.

You can craft specific ones at the Bench thingy mabobber.

Go to ravening pit and use the wrathful invoker at the end, make sure u click the right heart thing at the end tho

All of the above. It is the dark grey one.

Thanks all. Appreciate the help.