Feral was really easy play your rotation and kill the imps that places the voide zone.
Guardian was only hard until i understand the 2nd phase and how i need to play it. Some trinkets made this fight easier and i can only recommend to farm the seed from 1st raid in legion.
I had struggle to keep up with cc and healing with the 2 knife dancer adds and deal enough/fast damage in the 2nd phase to the eyes and the dude with bats below the stars. Trinket from hellfire wod raid helped me and the mechagon card trinket
After they “bugfixed” buffed the balance fight i am not able to beat this fight lol. Keep up with adds, hands and soak runes and at the same time damage the other stuff is nealry impossible compared to frost. I think i skip this fight because i will never do the 36/36 achievment.