To have important debuffs show up on the top left spot, please install this WA pack:
Plater - Debuff on Nameplate: https://wago.io/siwxrbGTR
(currently support Warlock/DH debuffs)
Arrows on the sides of the nameplates are from:
Ethric's Arrow Target indicators: https://wago.io/okQgj8zoy