you are a shadow, you hide in the shadows and you kill people silently

you have powers that make your job easy 

your powers inclued 

teleporting, becoming a shadow, linking souls or even messing with time itself

Level 3: abyssal abilites

You’ve trained to get into especially hard-to-reach places, granting you these benefits.

Climber. You gain a Climb Speed equal to your Speed.

Jumper. You can determine your jump distance using your Dexterity rather than your Strength.

Level 3: abyssal step

you can teleport 15ft as a bonus action 

you can't teleport through things but you can slip pass people

unlimited uses

increases to 30ft at level 11

Level 3: shadow kill

when you kill something that corpse disappears into the abyss

no one can see it now

Level 3: hand blade

you turn your hand into a blade
deals 2d10 slashing damage
turns to 3d10 at 9th level and 4d10 at 15th level

can turn in or out at will

Level 9: meld into shadow

At 9th level, you gain darkvison out to a range of 60 feet. If you already have darkvison from your race, its range increases by 30 feet.

You are also adept at evading creatures that rely on darkvison. While in darkness, you are invisible to any creature that relies on darkvison to see you in that darkness.

Level 9: abyssal attack

your sneak attacks deal 1d6 more nectrotic damage

Level 9: tendril hand

you extend you hand far enough to reach far places
you can grab objects or small or medium sized things from up to 15ft
the thing must make a str save of 13 or be pulled towards you

this has 5 uses + proficiency 

Level 13: shadow form

your abyssal powers allow you to transform into a shadow

in this form you are invisible to anything that doesn't have true sight

you have advantage on attack roles but you can attack 3 things before turning back

this has 3 uses turning to 5 at level 15

Level 13: bend time

as a action you can slow down time for 1 turn of combat

you gain a extra action and bonus action 

you movement speed increses by 20ft 

you get advantage on attack roles and saving throws

enemies can't opportunity attack you

this has 3 uses

Level 17: chain souls

as a bonus action you can link three peoples souls together so when you hurt one the other get hurt to and if one dies

you get the picture

 

this has 7 uses