Mastermind Revised

The Mastermind has already won. There isn't anything or anyone they won't use to their advantage. Beyond stealth and sabotage, these rogues utilize subtle manipulation and meticulous planning to meet their ends. They know that the real key to any treasure is the secrets and lies that people hold within them. 

Master of Intrigue

When you choose this archetype at 3rd level, you gain proficiency with the disguise kit, the forgery kit, and one gaming set of your choice. You also learn two languages of your choice.

Additionally, you can unerringly mimic the speech patterns and accent of a creature that you hear speak for at least 1 minute, enabling you to pass yourself off as a native speaker of a particular land, provided that you know the language.

Master of Tactics

Starting at 3rd level, you can use the Help action as a bonus action.

Additionally, once per round, you can use the Help as a free action. You can use this feature number of times equal to your proficiency bonus, and you regain all expended uses of this feature when you take a long rest.

When you use the Help action to aid an ally in attacking a creature, the target of that attack can be within 30 feet of you, rather than within 5 feet of you, if the target can see or hear you. 

Insightful Manipulator

Starting at 9th level, if you spend at least 1 minute observing or interacting with another creature outside combat, you can learn certain information about its capabilities compared to your own. The DM tells you if the creature is your equal, superior, or inferior in regard to two of the following characteristics of your choice:

• Intelligence score
• Wisdom score
• Charisma score
• Class levels (if any)

At the DM’s option, you might also realize you know a piece of the creature’s history or one of its personality traits, if it has any.

Whispers of Downfall

Beginning at 13th level, you can use your meticulous planning and schemes to sabotage a foe. When you use the Master of Tactics feature to use the Help action as a free action, you can instead of granting an ally advantage on their next attack roll or ability check, impose disadvantage on the next attack roll, ability check, or saving throw a creature within 30 feet of you would make.

Soul of Deceit

Starting at 17th level, your aptitude for schemes and mastery over your mind is so complete that you gain the following benefits:

• Your thoughts can’t be read by telepathy or other means, unless you allow it. You can present false thoughts by succeeding on a Charisma (Deception) check contested by the mind reader’s Wisdom (Insight) check.
• No matter what you say, magic that would determine if you are telling the truth indicates you are being truthful if you so choose, and you can’t be compelled to tell the truth by magic.
• When you use the Help as free action, either with the Master of Deceit or Whispers of a Downfall feature, you can affect two targets within 30 feet of you.