The Dark Slayer style is one of efficiency as well as one which allows you to cut down hoards of demons with great efficiency and unmatched speed. Teleport across the battlefield, untouched by all, and slay all, for this is your birthright. Let these powers assist you on your path to achieve power, more power. tey are not worthy to be your opponent.  

Devil Trigger

In this form, your damage rolls have 1 additional dice as well as resistance to bludgeoning piercing, and slashing weapons. Additionally, you regenerate hit points equal to your Constitution modifier (minimum of 1). By killing enemies you gain a charge to your devil trigger which is expended for every round you spend in devil trigger. Gain charges by killing enemies or by spending an action to taunt them. You can deactivate devil trigger at any time without using an action. Devil trigger is automatically deactivated if you fall unconscious. You amount of charges starts at three and increases to 5 at 7th level, 7 at 10th level, and 10 at 15th level. If your charges are below 3, your amount of charges goes up to 3 after a short or long rest.

Trick Step

You can use your reaction to attempt to dodge any attack made on you. Attacks will have disadvantage and dex saving throws will have advantage. 

Teleport

You can teleport 30 feet in any direction or to any enemy within 60 feet who you have hit with a summoned sword.

Archery

You gain a +2 bonus to attack rolls you make with ranged weapons.

Defense

While you are wearing armor, you gain a +1 bonus to AC.

Dueling

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Great Weapon Fighting

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Protection

When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.

Two-Weapon Fighting

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Doppelganger

Summon a translucent figure to fight with you. The figure takes up the space to your right. If any creature is within 5 feet of you, they are pushed back 5 feet. Your damage is doubled while the doppelganger is active. The doppelganger expends a bar of your devil trigger for every round he is out. He can be recalled, which requires no action. He has as many hit points equal to half yours. 

Judgement Cut End

You target any enemy of your choice within 60 feet. They take 1d20 damage plus your constitution modifier.