Shadow Assasin

Shadow assassins are extremely rare and were hunted down to near extinction. It is very hard to find one, let alone become one. In order to tap into the power of shadowfell, they have to train, day and night. Working on their physical health, as well as their willpower and will strength. Shadowfell favors shadow assassins as kin and is considered the native plane of a shadow assassin. If you wish to find one, you are truly looking for a quick death, as they are ruthless and hard to catch, let alone kill. You don't find a Shadow assassin, a shadow assassin finds you.

Shadow Step

At 3rd level, you can briefly channel shadow fell, and step into the shadows to appear at an unoccupied space within a designated range, you can use this to teleport up or down, but you still have the specified range for how much you can move down or up. The range is 10ft at 1st level, 15ft at 6th level, 20ft at 11th level, 25ft at 16th level, at 30ft at 17th level. Your movement speed on your turn is reduced by how much you teleported. For example, someone with 30ft movement speed teleports 10ft up into a tree, they have 20ft left that they can use as a movement action.

Stealthy Assasin

At 3rd level, you gain proficiency in Stealth. If you already have proficiency in Stealth, you gain proficiency in a skill of your choice.

Shadow Assassinate

At 9th level, you become very proficient at using your shadow step to your advantage against enemies. When you use your shadow step to teleport behind someone, you gain advantage on the attack roll and gain a sneak attack on the roll if it wasn't already granted. You double the damage on sneak attack if you do hit. This does not work against someone who cannot be surprised or has truesight.

One with Shadowfell

At 13th level, as a bonus action, you may turn invisible if you have used your shadowstep to teleport somewhere that is in dim light or darkness. The invisibility ends if you take an action or use your shadowstep to teleport somewhere that is not in dim light or darkness. You gain advantage on Stealth(DEX) checks and attacks on you gain disadvantage. You can trigger your Shadow Assassinate if you attack someone while invisible.

Shadow Trance

At 17th level, once per long rest, as an action, you can enter a shadow trance, which lasts 1 minute. During the trance, you are invisible and automatically succeed on Stealth(DEX) checks against people trying to find you. A creature with Truesight can see you, but can only see a purple blur and cannot see if you are holding a weapon or preparing to attack. While in shadow trance, you gain the effects of One with Shadowfell, but you do not break your invisibility if you attack a creature, and if you hit with your weapon, the damage roll is an automatic crit.