Sorcerers Apprentice
Hero
That's one case where Hunter's Mark is better, it gives you advantage on any check to track the marked target, so they won't be escaping easilyWhat sucks for the warlock is when you Hex a target, but are unable to bring them to zero HP. (i.e. the target successfully escapes.) At that point, you can't move that Hex to a new target - you have to stop concentration and recast Hex from scratch.
