Shadowblade

Shadowblades will take on an almost unearthly shine to their eyes are a dullness to their complexion coming from their time in the shadows.

Unearthly Stillness

Starting at 3rd level, when you take the shadow weaver archetype is standing still in dim light or darkness it becomes near invisible, doubling its stealth modifier. If the shadow blade moves they must make a dex/int saving throw. By 11th level, players may move while keeping their modifier bonus. You remain invisible until you make an attack, cast a spell with verbal components or creates light, or leave the area of darkness. This may be used 1/2*lv times between short rests. 

Shadow's Grace

Starting when you choose this archetype at 3rd level, you can use your action/bonus action to duplicate the effects of certain spells. As an action/bonus action, you can cast darkness darkvision, pass without trace, or silence without using components. Additionally, u gain the minor illusion cantrip if you don't already know it. At 9th lv if you have darkvision you can see through your own casting of darkness.

Shadow Step

At 9th level, you gain the ability to step from one shadow into another. When you are in dim light or darkness as a bonus action you can teleport up to 60ft to an unoccupied space you can see that is also in dim light or darkness. You then have advantage on the first melee attack you make before the end of the turn. 

Opportunist

At the 13th level, you can exploit a creature's momentary distraction when it is hit by an attack whenever a creature within melee distance of you is hit by an attack made by a creature other than you, you can use your reaction to make a melee attack against that creature. 

Shadow's strike

Starting at 17th level, the shadow's have become one with your blade. When you attack and hit a creature that you have advantage against it must make a Constitution saving throw (dc 8 +dex modifier + proficiency bonus.). On a failed save, deal necrotic damage equal to the attack on the creature (deal double damage and half of the damage is necrotic).