Inquisitive Redux

As an archetypal Inquisitive, you excel at rooting out secrets and unraveling mysteries. You rely on your sharp eye for detail, but also on your finely honed ability to read the words and deeds of other creatures to determine their true intent. You excel at defeating creatures that hide among and prey upon ordinary folk, and your mastery of lore and your sharp eye make you well equipped to expose and end hidden evils.

Hound for Deceit

Beginning when you pick this archetype at 3rd level, you develop keen senses for picking lies and hidden objects. You can take the Search as a bonus action, as part of your Cunning Action.

In addition, you may use Intelligence, instead of Wisdom, as the ability score for the Insight skill, and you have advantage on any checks with the skill made to determine if a creature is lying.

Inquisitive Fighting

Also at 3rd level, you gain the ability to decipher an opponent's tactics and develop a counter to them. As a bonus action, you make an Insight check against a creature you can see that isn't incapacitated, contested by the target's Charisma (Deception) check. 

If you succeed, you learn all of its damage vulnerabilities, damage resistances, damage immunities, and condition immunities; and you can use your Sneak Attack against that target even if you don't have advantage on the attack roll, but not if you have disadvantage on it. This benefit lasts for 1 minute or until you successfully use this feature against a different target.

Predicting Warrior

At 9th level, you may attempt to predict a foe’s next move. As a bonus action, you can make a Insight check against a creature you can see within 60 feet of you, contested by the target's Charisma (Deception) check. If you succeed, you manage to predict their next move. The DM tells you, at this moment in the initiative, what the creature plans on doing on its next turn. 

Afterwards, when the target takes its action on its next turn, you can use your reaction to make a single weapon attack against them. This attack has advantage and scores a critical hit on a 19 or 20 on the d20. If the creature’s action is the same as you predicted, and their plans haven’t changed since you analyzed it, the attack scores a critical hit on an 18, 19 or 20 on the d20, instead.

In addition, you gain a bonus to your next saving throw caused by the creature against you equal to your Intelligence modifier; and once you succeed on the check, you can’t use this feature again until you finish a short or long rest. 

Unerring Eye

At 13th level, you gain the following features: 

Steady Eye. You gain advantage on any Wisdom (Perception) or Intelligence (Investigation) check if you move no more than half your speed on the same turn.

Eye for the Uncanny. As an action, you can sense the presence of illusions, shapechangers not in their original form, and other magic designed to deceive the senses within 30 feet of you, provided you aren't blinded or deafened. Make either a Wisdom (Perception) or Intelligence (Investigation) check, your choice, contested by the effect’s save DC. On a success, you are aware the effects are happening, and you can choose one of them to end. You can use this feature once, regaining the ability to use it again when you finish a short or long rest. 

Eye for Detail. Your attack rolls against the creature analyzed by your Inquisitive Fighting  and Predicting Warrior features cannot have disadvantage.

Eye for Weakness

By the time you’ve reached 17th level, you learn to exploit a creature's weaknesses by carefully studying its tactics and movement. While your Inquisitive Fighting feature applies to a creature, your Sneak Attack damage against that creature increases by 3d6; and if you learned the creature possesses any damage vulnerabilities, you may have your Sneak Attack’s damage type become that damage type the creature is vulnerable to, rather than your weapon’s damage type.