Level 3: Charming, Code Maker, Bookish****
Level 9: Barked Order, Greater Charm, Irresistible, Information Broker**, Master's Gaze***, Tactical Move*
Level 13: Greater Irresistibility, Powerful Manipulator, Tactical Advantage*, Tactical Retreat*
Level 17: Mind Over Matter, Tactical Genius*
*: from the Lead Fighter subclass
**: from the revised Inquisitive Rogue subclass
***: from the revised Battle Master Fighter subclass
****: from the revised Rogue Thief subclass
Whenever a Mastermind subclass feature requires a saving throw, the DC is equal to 8 + your proficiency bonus + your Charisma or Intelligence modifier.
Starting at 3rd level, after speaking for a minute to a humanoid within 5 feet of you that can hear you and understand you, you can attempt to charm them. If you do, they must make a Wisdom saving throw, and does so with advantage if you or your companions have fought them or they know you have fought one or more of its allies. If they fail the saving throw, they are Charmed by you for 20 minutes per Rogue level you have or until you or your companions do anything harmful to them or one of their allies. The Charmed creature regards you as a friendly acquaintance.
You can use this feature a number of time equal to your Charisma modifier. You regain all expended uses after finishing a long rest.
A target that succeeds on the saving throw is immune to the effect of your Charming feature for a number of weeks equal to their Charisma modifier (minimum of 24 hours).
Starting at 3rd level, when you create a code or encrypt a message, the deciphering DC is equal to 8 + your proficiency bonus + your Intelligence modifier, and they are so difficult to decrypt that anyone attempting to do so has disadvantage to their Investigation skill check roll.
Starting at 9th level, as a bonus action, you can loudly bark an order to a creature you can see within 60 feet of you, as per the Command spell. You can use this feature a number of times equal to your proficiency bonus, you regain all expended uses after finishing a short rest.
Starting at 9th level, humanoids have disadvantage to their saving throw while trying to resist the effect of your Charming feature. You also now regain all expended uses of your Charming feature after finishing a short rest.
Starting at 9th level, with your Charming feature, you can now affect any intelligent creature, not just humanoids, as long as it can hear you and understand you.
Starting at 13th level, your Irresistible feature now affects any intelligent creature, not just humanoids, as long as it can hear you and understand you.
Starting at 13th level, a humanoid you successfully Charmed with your Charming feature now see you as very close acquaintance and trusts you. There are few things they would not do for you. However, they will not endanger themselves or their allies under any circumstances. If something risky is proposed to the target, they get to roll another Wisdom saving throw with advantage, disregarding the Irresistible feature.
Starting at 17th level, you can use your Charisma or Intelligence modifier instead of your Constitution or Strength modifier for your ability checks. Also, your Charming feature now takes only an action instead of a minute.