in "BW/DBM ability <= 10s" go into Display, scroll to bottom and press "Add Glow" - have this glow turned off by default.
then go into Conditions and add a condition for if trigger 1: Message: <boss ability name> then Glow 1 Visibility on. (alternatively can use ID instead of message if you know the IDs).
then repeat same for "BW/DBM ability >10s" if you want the glow active there too.