That feeling of scaring the players

[Gizmo]

The DM's job is not to kill the party. Nor is he out to destroy them. His role is to provide a story line, control the monsters, have the world react to their decisions, and provide them a challenge. All of this is done inside the rules of the system you choose to run, in this case FFd20. While terror can be caused multiple ways in a game, and a fear intended game is all great, it should be out of the environment and things going on that cause that, not the DM trying to kill them.

Take caution in why you are enjoying bringing terror to their characters.