So I made a skill based off Veil of Shadows, and it shows in the skill tree, you can put points in there, however when I go to assign it to the hot bar at the bottom it is not an option. I double check everything against the vanilla skill and I dont see anything in there that would prevent this.
It should just be a toggle aura like many of the other skills in the game.
This is where I wasnt sure since I was copying a vanilla skill. It looked like they used a base skill almost like a placeholder then used the skill with a modifier to make the aura? perhaps I need to add both the base and the modifier to the skill list?
You assigned the buff directly to the skill tree, you need to assign the skill that controls the buff to the skill tree (ie. FabricOfReality.dbr instead of FabricOfReality_Buff.dbr)