Battle Manipulator

Many Rogues exploit the weaknesses in their opponents. But you specialize in manipulating the battlefield to stack the odds in your favor. Members of this archetype are fantastic at influencing, perceiving, and finding flaws in their opposition. 

Tools of Manipulation.

3rd-level Battle Manipulator feature

Starting at 3rd level, you gain proficiency with the poisoner's kit. Also, if you spend at least 1 minute observing or interacting with another creature outside combat, you can learn certain information about its greatest defenses and weakest traits. The DM tells you the creature's highest saving throw and its lowest saving throw.

Exploitation

3rd-level Battle Manipulator feature

At 3rd level, you have learned how to manipulate the cracks in your foe's defenses using "Exploits". Immediately after triggering your Sneak Attack ability, you must check the "Exploit Table". For each exploit you have fulfilled you gain the corresponding benefits from the "Exploit Rewards" section. The rewards are cumulative beyond the 3rd. You gain additional exploits at 9th, 13th, and 17th level.

Exploit Table.

• If another enemy of the target is within 5 feet of it, that enemy isn’t incapacitated.
• If you are hidden from the target. (see  "Unseen Attackers and Targets" in the Players Handbook.)
• If you haven’t moved during this turn, and after this, your speed is 0 until the end of the current turn.
• If you have moved outside the target's melee range during the current turn.
• If the target or you are currently prone.
• If your roll to hit for the attack (including modifiers) was 5 or above there armor class.
• The target is blinded, deafened, restrained, or poisoned.
• You may use your reaction to gain this exploit.

Exploit Rewards. These rewards are numbered by how many exploits you have achieved. After you achieve three or more exploits, ignore the first two levels of the rewards. The first two levels of the rewards do not stack.

1. 1- Roll d6 less for this sneak attack.
2. 2- Roll d6 less for this sneak attack.
3. 3- Roll an additional d6 on this sneak attack.
4. 4- Add your proficiency bonus to the damage of this attack.
5. 5- You may knock the target prone.
6. 6- You may treat any 1 or 2 rolled for damage during this sneak attack as a 3.
7. 7- The target becomes blinded,  deafened, or poisoned until the end of your next turn.
8. 8- Roll an additional d6 on this sneak attack.

Seeker of Flaws

9th-level Battle Manipulator feature

Starting at 9th level, You gain advantage on Intelligence (History), (Investigation), Wisdom (Insight), and (Perception) checks to find weaknesses of a creature or object you have seen.

You have learned more insights into flaws to exploit. You gain two new "Exploits".

• If you have used "Uncanny Dodge" and/or "Evasion" within the last round.
• If you have used "Tools of Manipulation" on the target within the past 24 hours.

Expedited Fall

13th-level Battle Manipulator feature

Starting at 13th level, you may use "Tools of Manipulation" as an action rather than examining the creature for 1 minute.

You have learned even more insights into flaws to exploit. You gain two new "Exploits".

• If the target is two sizes larger or smaller than you.
• If the target is concentrating.

Fatal Flaw

17th-level Battle Manipulator feature

Starting at 17th level, you are able to spring into action in response to a creature's momentary weakness. When a creature within 30ft of you fails a saving throw, you may use your reaction to make an attack against it with a weapon you are holding. You may add 2 "Exploits" to this attack without needing to achieve them. Once you use this feature you may not use it again until you have completed a long rest.

You have learned a simple yet effective flaw to exploit. You gain two new "Exploits".

• If this attack is a critical hit.

You can find a singular point to devastate an opponent. You gain a new "Exploit Reward".

  10.10- You cut off one of the creature's heads. The creature dies if it can't survive without the lost head. A creature is immune to this effect if it is immune to all the damage of the attack, doesn't have or need a head, has legendary actions, or the GM decides that the creature is too big for its head to be cut off with this weapon. Such a creature instead takes an extra 6d8 damage from the hit.