"D-Don't let them get me! Help! Help! HELP-"
-A Victim.

Through some way or another, be it madness from war, a psychotic break, or you always just being sick in the head, you have become a masked, mass murderer. Luckily your mask has prevented anyone from tracking you down.

(I'm still iffy on if this should be a barbarian subclass instead, feel free to remake this as a barbarian subclass, just credit me okay? Okay.)

Level 3

Muted Approach: When making a Stealth check, you may replace Dexterity with Strength. However, you must be wearing medium or lighter armor.
At level 7, during a surprise round, all of your attacks have advantage, and you do not lose a turn if you are surprised.
At level 15, At the start of combat, if you are not incapacitated, you can attempt to hide as a free action.

Raging Pace: As a bonus action, you can enter a cold, calculated rage. When you activate Raging Pace, your movement does not provoke opportunity attacks, and your reach with your next melee attack increases by 10 feet. After making an attack in this state, or after 3 rounds, it ends. You can use this ability again after killing a creature.
At level 7, you also deal an additional die of damage with attacks enhanced through Raging Pace.
At level 15, you deal 2 additional dice of damage instead, and you cannot be Stunned, charmed, or frightened during Raging Pace.
At level 18, during the first round of Raging Pace, you are fully immune to Slashing, Piercing, and bludgeoning damage, and you gain resistance to all other types of damage (other than psychic), you can also use Raging Pace as a reaction to an attack on you.

Brutish: Your unarmed strikes deal extra damage equal to your proficiency bonus, and you can move at your full speed when grappling a creature of your size or smaller.
At level 10, the grapple effect also activates on creatures 1 size larger than you, and you can grapple creatures 2 sizes larger than you.
At level 15, the grapple effect also activates on creatures 2 sizes larger than you.

Level 7

Killer's Toolbox: You gain 3 "cunning" points, Cunning is consumed to use special attacks. You get 1 Cunning back when killing a creature or when a creature you've damaged that's below half health dies. You regain all Cunning points at the end of a short or long rest.
At level 10, your max Cunning points increase to 4.
At level 15, your max Cunning points increase to 5.
At level 18, your max Cunning points increase to 6.

Cunning; Disabling Strike: By spending 1 Cunning, the next attack you make against a creature makes them Helpless until the start of your next turn on a hit. If used during Raging Pace, the creature is made Helpless for 2 rounds instead.

Grapple and Cut down: When making an attack with a one-handed weapon, or an unarmed strike, you can target creatures you are grappling with attacks, and you deal bonus damage equal to your Intimidation modifier.
At level 15, creatures you grapple have disadvantage on escaping the grapple.
At level 18, if a creature your size or smaller attempts to escape your grapple and fails by 7 or more, you break their neck. If the creature cannot live with their neck broken, they die, else, they take 5d12 bludgeoning damage

Helpless (Condition)

A helpless creature is overwhelmed and unable to act effectively.

• A helpless creature can’t take actions, bonus actions, or reactions.

• It can still move, and may use the Dash or Disengage actions.

• Attack rolls against a helpless creature have advantage.

• The creature has disadvantage on Strength and Dexterity saving throws.

Level 10

Cunning; Gouge: You can spend 1 Cunning to make a Gouge attack in place of a regular weapon attack. When landing a Gouge attack, the hit creature becomes blinded for 2 rounds, and takes 1d6 typeless damage at the start of their turn until they can stop the bleeding. After this attack, even if you hit, your movement speed becomes 0 until the start of your next turn as you regain your stance. If used during Raging Pace, they become blinded for 4 rounds instead, they take 2d4 typeless damage at the start of their turns, and your movement speed is reduced by 10 instead of becoming 0.

Prey Mark: The first creature you damage in an encounter becomes your "Prey", you deal +3 damage to your Prey, and you know their location whenever you're in Raging Pace (as long as they're in the same plane as you), even if they're invisible. You can choose to change your Prey at the start of your turn to another creature you have damaged.
At level 15, all creatures below half health have their locations revealed to you when you use Raging Pace.
At level 18, you deal +5 damage to your Prey instead.

Level 15

Cunning: Gashing Wound: You can spend 3 Cunning and an action to make a Gashing Wound attack, if you hit, you deliver a ruthless combo on the enemy. After landing this attack, you may make a Melee weapon attack at the start of each creature's turn (up to your proficiency bonus) that is guaranteed to hit. If your turn were to start again before you have used all of your attacks, make all remaining Gashing Wound attacks at the start of your turn. While Gashing Wound is active, if the target is your size or smaller, their turn is skipped.

Brutalizer: When landing an attack on a creature, roll a d4 and inflict one of the following effects (Once per creature per turn, does not trigger on Cunning attacks):
1. The Creature becomes deafened.
2. Enemy Creatures within 20 feet of you must make a DC 8 + (Your proficiency bonus + your intimidation modifier) wisdom saving throw, becoming frightened of you until the start of your next turn of a failure.
3. The Creature must make a DC 6 + (Your proficiency bonus + your intimidation modifier) constitution saving throw or become stunned until the start of your next turn.
4. The creature drops whatever items it was holding, and you gain 1 Cunning.

Level 18

"... ... ... ... ..."
-The Original Slasher

A Grave Soul (Now Run): Your movement speed increases by 20 feet, you gain a climbing speed equal to your walking speed, your push, drag, lift, and carry weight are doubled. You can have 2 charges of Raging Pace stored at a time, all damage you deal with melee weapons or unarmed strikes gain an extra die of damage (stacking with Raging Pace), you gain proficiency in Constitution and Death Saving throws, and you gain expertise in Intimidation.