Magic:
Hex: It can be a bread and butter spell for early levels of Warlocks in 5e, however the fact that it is currently not transferable upon kill makes it useless(I assume that's a small over sight or a current systems limitation^^). However, you might even consider making the spell work better with Warlocks inherent spell slot upscaling and increase the dmg it deals at higher levels as in 5e only the concentration duration increases which in turn means it'll still become a wasted slot later on.
Killing an enemy marked with Hex allows you to recast it as a bonus action without consuming a spell slot, you should see a new hex icon appear on your hot bar when it's available
