Dragon’s Terror. You can take a Magic action to instill terror in a creature you can see within 30 feet of yourself. The target must succeed on a Wisdom saving throw (DC 8 plus your Wisdom modifier and Proficiency Bonus) or have the Frightened condition until the end of your next turn. If the target succeeds on the save or when the effect ends for a target, the target is immune to this effect for 24 hours.
Inspired by Fear. When you cause a creature to have the Frightened condition and you are the source of its fear, you can gain Heroic Inspiration if you lack it. Once you use this benefit, you can’t use it again until you finish a Short or Long Rest.
It seems to be a way of getting Inspiration fairly reliably.. I'll say that I'm a little surprised it isn't based off of Charisma, but I guess Wisdom is a cleric stat and you're a cultist, so..
I also think it should be Intimidation, not Deception.
The Cult of the Dragon might be based on a big lie (although technically Sammaster legitimately believed his mistranslated section of the prophecy was true), but overall the cult runs on fear.
It is a correct assumption 99% of the time, because stats are highly limited and story is free
Occasionally players will purposely play a gimped build but the game should not be designed around requiring this to be true for any particular game choice to be useful.
The Cult of the Dragon might be based on a big lie (although technically Sammaster legitimately believed his mistranslated section of the prophecy was true), but overall the cult runs on fear.
The idea that Sammaster mistranslated the prophecy predates WotC. It’s from TSR’s 2e Cult of the Dragon book.
(I did a lot of research into the Cult of the Dragon back when Tyranny of Dragons was new; the setup in that adventure is actually remarkably faithful to the pre-5e canon, building on what came before. One of the older FR books even established that Tiamat’s cult was infiltrating and subverting Cult of the Dragon cells before the Spellplague.)
I think the background would be okay on dex based Battlemaster fighters with menacing strike. The stats align well enough. The feat is decent if you commonly cause fear. Even if you never use the wisdom based fear. But the Battlemaster fighter could have Wis as a tertiary and still make decent use of that.