The abyss watchers emulate the fighting style of Artorias, a knight who stood against the abyss alongside his companion, the great gray wolf Sif. They will destroy the slightest trace of the abyss, and destroy kingdoms to do it. Abyss watchers wield a greatsword in one hand and a dagger in the other, inspired by how Artorias The AbyssWalker fought alongside Sif. They execute complex maneuvers with their weapons, making even a single one a terrible foe

Greatsword and dagger

When you choose this archetype at 3rd level, you can wield a greatsword in one hand effectively, as long as you are wielding a dagger in the other hand. When wielding a greatsword this way, it counts as a light weapon for the purpose of dual wielding.

Watcher techniques

At 3rd level, you learn techniques for complex usage of your weapons, moving quickly around the battlefield and striking at your enemies. which can only be used if you are wielding a greatsword and a dagger.

-Techniques. You learn 2 techniques of your choice. You learn the 3rd at the 7th level, the 4th at the 11th level, and the 5th at the 15th.

-Technique points. You have a number of technique points equal to your fighter level +2, and you can use them to perform techniques.

-Follow-ups. Some techniques have follow-ups, detailed at the end of the technique. You can use the follow-up of a technique after using that technique as a bonus action, and cannot do so any other time. If you move after using a technique, you can't use the follow-up.

-Limit. you can use 1 technique per round. (daggers parry is an exception "once as a reaction")

Dagger parry

As a reaction to being hit by a melee attack, you may expend a technique point to roll a 1d6 and add the result to your ac against that attack, potentially causing it to miss.

at 13th 1D6 + 1D4

follow up. You may expend 2 technique points to make a melee attack against a creature you caused to miss his attack with this feature. attack once with your greatsword with advantage, and automatically be a critical hit if you hit.

Lunging stab

You may expend two technique points to use your attack action to move up to your walking speed in a straight line, expending the same amount of movement. This movement does not provoke opportunity attacks. If at any point during this movement, there is a creature directly in front of you within reach of your greatsword, you immediately stop your movement and make an attack against that creature with your greatsword. On a hit, the target takes piercing damage instead of slashing, and an additional 1D8 force damage. This extra damage can only be dealt once per use of this technique.

the greatsword attack can be followed up with the dagger.

You must be able to move at least 10 feet in the direction you choose to move in to use this feature.

at the 7th 2D8 and at the 15th 3D8 (FORCE DMG)

Relentless assault

As an attack action, you may expend one technique point to make a quick attack with your dagger, then one with your greatsword. If the dagger hits, your greatsword attack has an advantage. You can only use this technique if you make at least one greatsword attack and a dagger attack your previous turn, and didn't move more than 10 feet after doing so.

Follow up. As a bonus action, you may expend 1 technique point to make a greatsword attack against each creature within 5 feet of you. 

Spinning lunge

As an attack action, you may expend 2 technique points to move 10 feet in a straight line without provoking opportunity attacks and make a greatsword attack against each creature within reach of your greatsword. targets must roll DEX save of 8+prof modifier+streath modifier; on success take half damage.

10/15 feet range on the 13th 

Follow up. After you stop you may use your bonus action to expend 1 technique point to make a greatsword attack against each creature within reach of your greatsword. dealing greatsword damage and extra 1D6 Force damage.

Watcher's strike

As an action, you may expend 2 technique points to make a greatsword attack against a target within reach. On a hit, you deal an extra 2d6 damage for each attack you can make with the attack action (this includes the offhand attack with the dagger), and the target is knocked prone, as you make an upwards swing that tosses them in the air.

You can only use this technique the turn after making at least one greatsword attack and a dagger attack the previous round and not moving after doing so.

at the 9th level 2D6, at the 18th 3D8

Wolf's strike

As an attack action, you may expend 2 technique points to make 2 attacks with your dagger against the same target. If either attack hits, the next attack against the target has an advantage.

 at the 8th level 2D6, at the 16th level 3D6.

Technique points

You have a number of technique points equal to your fighter level +2, and you can use them to perform techniques.

resets on short rest

Abyssal Speed

Beginning at the 7th level, you have harnessed the art of dashing across the battlefield.
Gain moblie feat. Gain Expertise with Athletics.

Sif's Blood

you can summon with your dagger a blood shard from The wolf Sif of the AbyssWalker, and ignite it with your Greatsword to ignite it with fire.

At the 10th level, As a bonus action, ignite your greatsword with fire. For one minute, you deal an extra 1d12 of fire damage with all of your greatsword attacks. and any creature within 5 feet of the attacked creature takes the fire dmg.
at the 16th level 2D12.

can be used twice per Short rest. even if you are incapacitated the flame doesn't extinguish.

Flaming dash

At the 15th level, you can dash across the ground, dragging your greatsword through it, causing flames to flare up a split second later. As an action, you can expend 4 technique points to move up to 50 feet in a straight line without provoking opportunity attacks.
Each creature in your path must make a con saving throw or take 14d6 slashing damage, and half as much on a successful one, then dex saving or take 14d6 fire damage, or half as much on a successful one. <DC = 8 + prof modifier + strength modifier>

-does not consume speed
-You must be wielding a greatsword and a dagger and be under the effects of Sif's Blood to use this feature.
-once per 8 rounds

Watcher's expertise

Starting at the 18th level, as a special action you may use a watcher technique and expend 1 less technique point. You can't use this feature again until the beginning of your next turn.