From Dark and Darker Wiki
Maybe try to use it situationally instead of all the time; wait until you have the drop on a rondel buckler pdr fighter and channel before rushing in to one shot them with a bardiche or perhaps perform a full channeled 5 shard dark bolt from across the map on an unsuspecting ranger who is about to loot a lion's head. Maybe you are being pursued by a barbarian and you manage to hit him with an instance of bloodstained blade to deafen him; giving you the chance to drop into a previously darkened pit and channel for a quick dps boost; knowing that if you tried to fight him without it you would have been one-shottable by his double axe whether you were 100% hp or 10%. At least now you can one shot him too...
Warlock rewards creativity, preparation and calculated risk. The buff duration build is highly specific and I believe not really the intended usage for this skill; use your imagination and most of all have fun. And remember, off meta becomes meta in the eternal dance of the battle of the subclasses