Ripper

"They spoke of a man who prowled the city at night. One who was not found once, but of whom vast and vastly grotesque evidence was acquired. Those who have witnessed his horrific works claim him to be a blur of motion, a whirlwind of death itself. Men standing proud and watchful would dissapear as you turned your eye, however briefly, replaced with a pile of gore. A knife's brief glint is all known of this man; that and the grisly work he leaves behind."

 

-Ajax Karmyn, Personal Journal, page 935: The Shadow of Dolques

 

Rippers do exactly as their name would suggest. With a style contrary to most other rogues, these oft unstable assassins dart around the battlefield, able to rip individual enemies to shreds in moments with a flurry of visceral yet surgical strikes.

Level 3: Living Whirlwind

A few basic traits are homed in all Rippers, manifesting in the following benefits:

• You learn the two-weapon fighting style. If you already know this fighting style, you may pick another of your choice.
• You gain a climbing speed equal to your walking speed, and calculate the distance of running jumps using your Dexterity modifier.
• When you hit a creature with a melee attack, it cannot target you with opportunity attacks until the end of its next turn. 
• You gain proficiency with Medicine and with Intimidation. If you already have proficiency in either of these, you gain expertise.
• You ignore obscuring rules by smoke, mists, and similar effects. While lightly or heavily obscured by smoke, mist, or a similar effect, you are considered invisible. 

Level 3: Bloodthirst Trance

As a Bonus Action, you can choose to enter a Bloodthirst Trance for one minute. While entranced, you gain the following benefits:

• Your movement speed increases by 5 x your proficiency bonus.
• You do not need advantage on an attack roll to use your sneak attack if you move at least 5 feet in a straight line before attacking the creature.
• When entering within 5 feet of a creature after moving at least 5 feet in a straight line, you may make a melee attack. This attack allows you to add half your sneak attack dice to the damage (round up). You may make an extra attack in this way once. You gain additional uses of this attack at level 5 and level 17. If you have additional attacks, they may use this way of dealing additional sneak attack damage.
• When you make a thrown weapon attack towards a creature, regardless of if the attack hits, you may use a reaction to dissapear and teleport behind the creature. Alternatively, on any throw, you may target an unoccupied space with this throw and teleport there.

The Trance ends after one minute or until you end it as a bonus action. When you reduce a creature to 0 hit points while entranced, you can reset its duration. You have a number of uses of the Trance equal to your proficiency bonus, and regain expended uses at the end of a long rest. 

Level 9: Surgical Precision

When you deal sneak attack damage to a creature, you may choose a relevant Surgical Strike to make. Saving throws against your Surgical Strikes have a DC Equal to 8 + your Proficiency bonus + your Dexterity modifer. Each time you use a Surgical Strike on a creature, roll a d20. On a 20, you use the Fatal Blow of that strike. At your DM's discretion, bosses or creatures with incompatible anatomy may not be eligible for fatal blows.

• Gut Slice. When you deal Sneak Attack damage to a creature from directly in front of them, you may sacrifice 2d6 of your Sneak Attack dice to slash their gut. While slashed, a creature has disadvantage on attack rolls and Strength, Dexterity, and Constitution saving throws. A creature that starts its turn slashed takes 2d6 Necrotic damage. When a slashed creature ends its turn, it may make a Constitution Saving Throw. On a success, it ends this effect. Fatal Blow: You disembowel the creature, and it falls prone and incapacitated in addition to the already present effects. If the creature is healed or capable of healing itself, this effect ends.
• "Favorite hand?" When you deal Sneak Attack damage to a creature from in front of them or the direction of a limb which they are holding a weapon, you may sacrifice 1d6 of your Sneak Attack dice to force them to make a Strength Saving Throw. On a failure, the creature drops their weapon and suffers disadvantage on attack rolls until the end of its next turn. Fatal Blow: You sever the creature's hand.
• Popliteal Artery. When you deal Sneak Attack damage to a creature from behind, you may sacrifice 2d6 of your Sneak Attack dice to slash the back of their knee. The creature must make a Dexterity Saving Throw or have its movement speed reduced to 0, regaining 5 feet of movement at the start of each of its turns, as its knee gives out when applied too much pressure. While its speed is at least halved by this effect, the creature has disadvantage on Strength and Dexterity Saving Throws. On a success, its speed is reduced by 15 feet. Fatal Blow: You rip the muscles and artery severely enough that the creature falls prone and its movement speed remains 0 until it receives healing. The creature takes 2d6 Necrotic Damage at the start of each of its turns while this is happening.
• Between the Ribs. When you deal Sneak Attack damage to a creature from either of their flanks, you can sacrifice 3d6 of your sneak attack dice to force the creature to make a Dexterity Saving Throw. On a failure, you jam your weapon between their ribs. You leave the weapon used in them, and while it remains in them,  they have disadvantage on all ability checks, saving throws, and attack rolls until it uses an action to remove the weapon, taking 3d6 Slashing Damage for each round it ended with your weapon embedded in it. You may, on your next turn, remove the weapon from the creature yourself replacing an attack, dealing the potential damage maximized. Fatal Blow: You reduce the creature to 0 hit points, as you pierce its heart or some other vital organ.
• Throat Slash. When you deal Sneak Attack damage to a creature from directly in front of it, you may sacrifice 2d6 of your Sneak Attack damage to slash its throat. The creature must make a Dexterity Saving Throw or be unable to speak or perform verbal components of spells until it receives healing, receiving 1d6 Necrotic damage at the end of each of its turns. Fatal Blow: The creature falls prone, and is reduced to 0 Hit Points at the end of your next turn as it bleeds out swiftly.
• Reach Around. When you deal Sneak Attack damage to a creature from behind, you may sacrifice 1d6 of your Sneak Attack damage to immediately grapple them. While grappled in this way, the creature cannot speak, and you have advantage on attack rolls and may make your Bloodlust Trance attacks without extra movement. When a creature contests your grapple,  you may use your Acrobatics bonus instead of Athletics when rolling to maintain the grapple.

Level 13: Extra Attack

You may attack twice, instead of once, when you take the attack action on your turn.

This extra attack may benefit from full sneak attack under the Bloodthirst Trance feature. 

Level 17: Paragon of Murder

You gain the following additional benefits while in Bloodthirst Trance:

• You gain Advantage on Strength, Dexterity, and Constitution saving throws.
• You may use Surgical Strike options with your additional attacks from Bloodthirst Trance.
• When you reduce a creature to 0 Hit Points, regain Hit Points equal to your level and restore your action and movement. This can only happen once per turn.

Additionally, when you roll initiative and have no uses of Bloodthirst Trance available, restore one use.