Shadow Stalker

Ethereal energy flows through the veins of the Shadow Stalker granting them spectral and ghostly abilities. The Shadow Stalker is an assassin that uses their gifts to their advantage, and are masters of stealth. 

Shadow Stalker Save DC

Some of your Shadow Stalker abilities require a saving throw. The DC for these saves is 8 + your proficiency modifier + your charisma modifier. 

Unseen Shadow

Starting at 3rd level, you gain proficiency in the survival skill, and are able to cast pass without trace without the use of a spell slot once per long rest. The use of pass without trace only applies to you, and cannot be extended to anyone else. There are no material components needed to cast this spell, however, you still need to use the verbal and somatic components. You can cast this spell twice per long rest when you reach 10th level.

Phase Shift

When you take this archetype at 3rd level, you can become intangible for a short amount of time. You can use an action to turn you and all of your belongings incorporeal for 1d4 + your charisma modifier rounds. While in this form normal attacks from non-magical weapons do not affect you and do not cause you to end your Phase Shift. However, if you are struck by a magical weapon of +1 or higher, or a silvered weapon, you take damage as normal and must make an intelligence saving throw to stay in your Phase Shift form. The saving throw DC for this check is 8 + damage dealt.

While in this form you are able to move normally, however, you are also able to move through walls and doors. You spend 3 feet of your movement for every 1 foot of material you pass through (minimum of 3 feet). If you end your Phase Shift inside of a solid object, you are jolted into the closest unoccupied space outside of the object and take Xd6 force damage, where X is the number of feet you were moved out of the object. For example: if you end your Phase Shift in a wall that is 5 feet thick, and the wall still has 2 feet of thickness left before you are out of it, then you are moved the remaining 2 feet and take 2d6 force damage. The increased use of movement speed does not apply to the number of damage dice used when calculating force damage. This ability does not allow you to pass through creatures, living or undead. However, you are able to Phase Shift through constructs.

You have advantage on stealth while in Phase shift and can use your action to make a sneak attack if you are not seen. If you miss on an attack roll while in Phase Shift you must roll a stealth check to not be noticed. In this form you are unable to pick up objects that are not already on your person or grapple enemies. This ability can be used twice per long rest, and increases to three times at 6th level, and four times at 12th level. 

Spectral Siphon

Starting at 9th level, once per long rest when you make a sneak attack while using Phase Shift, your sneak attack damage become necrotic and has a chance to siphon the life force from a living target. The target must make a wisdom saving throw against your Shadow Stalker Save DC, or have its hit point maximum reduced by the sneak attack damage dealt. The damage dealt this way cannot be healed by regeneration, healing potion, or a healing spell. The use of a greater restoration spell, or a long rest, is required to return the hit points lost in this way. You gain temporary hit points equal to half of the sneak attack damage dealt, rounded down, if the target failed their wisdom saving throw. These temporary hit points are lost at the end of a long rest if there are any remaining. This ability does not work on undead, constructs, or creatures who are immune to necrotic damage.  You are able to use this ability twice at 14th level, however, the second attacks sneak damage replaces your current temporary hit points you have, if any. 

Ghostly Thief

Starting at 13th level, you learn magics that allow you to move quickly and unseen. You learn the haste spell and are able to cast it without using a spell slot or matrial component twice per day. Also, while under the affects of your pass without trace ability you are also considered under the affects of the nondetection spell.

Spectral Possession

Starting at 17th level, you can take control of an undead or living creature's body. While using the phase shift ability, you can use your action to force your way into a creatures body. The creature must make a constitution saving throw against your Shadow Stalker Save Dc. Creatures who are immune to being charmed or frightened automatically succeed the save. A creature who is frightened, or intimidated by you has disadvantage on this saving throw.

On a failed save, you enter the creatures body and gain complete control. While in control of the creature you gain the creatures movement speed, weapon attacks, vulnerabilities, resistances, armor class, and immunities. When you speak, if the host has a known language and is able to speak, you use the creatures voice. This gives you advantage on charism (deception) checks while in the host. This does not allow you to speak any language the host might know that you do not. You also are unable to read the mind of the host, and this does not give you any insight into anything they might know. 

When you the host takes damage, you receive half of the taken damage rounded down. The host then makes another constitution saving throw against your Shadow Stalker Save DC. On a successful save you are jolted from the host and unable to possess them again for 24 hours. You also take force damage equal to Xd6, where X is the number over the save DC rolled. For example: your Shadow Stalker Save DC is 18, and they roll a total of 21. You receive 3d6 points of force damage from being jolted out of the host.

On a failed save, you retain control of the host, however, they may make a wisdom saving throw against your Shadow Stalker Save DC at the end of each of their turns from that round on. When you leave the host's body, by force or willingly, the host makes a wisdom saving throw against your Shadow Stalker Save DC to know if you were the one possessing them. On a successful save, the host becomes hostile towards you. On a failed save, the host has no knowledge of you possessing them.

The duration of the possession is a number of hours equal to your charisma modifier (minimum 1). You can end this ability early if you choose, and enter the nearest unoccupied space near the host. You are able to use this ability tice per long rest.