The Hallowed Knight

1. I made this for my friend and I have no clue what the game actually plays like, so it's not going to be accurate. I'm just twisting what he wants into a subclass for D&D.

2. Take it and remake it however you want 

Mist Vale

At 3rd level you can, when you take the Disengage action you can teleport up to half your movement after walking 10 ft.

If you do this and don't take an attack, hide, dash, or cast a spell as another ability either action, bonus action, or reaction, till the start of your, You gain resistance to all damage till the start of your next turn, all attacks have disadvantage, and you gain Darkvision up to 120ft. Note if you attack then disengage you do not receive the benefits listed above, just the teleportation up to half your movement.

Good arm

At 3rd level you can, when throwing an object like a dart, rock, ect. you have advantage on the roll. As well as if you are targeting a creature any thrown object that's not a dart deals 1d4 bludgeoning damage and Darts deal more damage equal to your rogue level.

You also gain proficiency in throwing objects that aren't darts

Soul Slash

At 9th level you can as part of your attack action you can expend 1 hp to exert your soul to hit all targets in a 5 ft area around you. You gain advantage on one attack and you only roll for how many attacks you can make regularly and that roll goes against all creature's AC and deals the same damage to each being that you have targeted  within your 5ft range.  You can only use this ability a number of times equal to your Con modifier. 

Soul Shot

At 13th level you can draw energy from your own soul. 

You focus its energy taking both action and bonus action. and any and every creature must make a saving throw of your choice with a DC of 13 + Proficiency Bonus + Con. You can use this ability once per day without any drawbacks, but you can use it more than once, you'll just have to make a Constitution saving throw each time you use it more than once. The DC starts at 10, but increases by 2 every time you cast it. Ie: 1 free, then 10, then 12, and so on and so forth.

The Beam is a 5ft by 5ft tall and wide while the range is of 50 ft. Anyone who fails their save take 6d8 radiant damage and are considered blinded till their next turn. All that save take a half the damage.

Void Tendrill

At 17th level you can summon all the power of your soul and sharpen it into a whip like fashion. As an action a 2 large tentacles emerges from your arms and they stay for up to a minute or until they are no longer wanted. While you have these tentacles as arms you can make 2 grapple attempts as a bonus action and gain a second attack. The range is of 15 ft and the to hit modifier for these tentacles are your STR mod. + DEX mod. + CON mod. and if the weapon attacks hit they deal 4d12 necrotic damage and count as finesse weapons so yes you can add sneak attack. You can use this ability once per day.