D&D 5e Homebrew Fighter Archetype - Abyss Watcher

[Diomitus]

I've seen a few variations of this going around over the years and I thought I'd give it a shot myself.
I welcome ant feedback


Level 3 - Abyss Watcher Archetype
Legion Fighting Style
When not wearing a shield or heavy armor you can wield a greatsword in one hand. You learn to use a dagger in your offhand as a fulcrum to gain leverage in order to swing the greatsword in this manner. To use this fighting style, you must have a dagger in your off hand. You cannot attack with the dagger as a bonus action, but it counts as wielding a secondary/finesse weapon for all other purposes.

Sense Corruption
The presence of strong evil registers on your senses like a noxious odor. As an action, you can open your awareness to detect such forces. Until the end of your next turn, you know the location of any monstrosity, fiend, or undead within 100 feet of you that is not behind total cover. You know the type (monstrosity, fiend, or undead) of any being whose presence you sense, but not its identity (the vampire Count Strahd von Zarovich, for instance). Within the same radius, you also detect the presence of any place or object that has been desecrated, as with the hallow spell. You can use this feature a number of times equal to 1 + your Wisdom modifier. When you finish a long rest, you regain all expended uses.

Level 7
Unpredictable Fighter
You can use a bonus action to Dash. At the end of this Dash, you gain a bonus to attack and damage rolls equal to your Dexterity modifier. Creatures who you make an attack against after taking this Dash bonus action have disadvantage on attacks of opportunity against you whether you hit or not.

Level 10
Wolf's Blood Pact
Your partaking of Wolf's blood has made you extraordinarily resilient. When you are reduced to 0 hit points and not killed outright, you regain a number of hit points equal to your Con modifier x half your fighter level. You regain the use of this feature after you finish a long rest.
Additionally, your weapons are considered magical for the purpose of overcoming magical resistance and immunity to non-magical attacks.

Level 15
Improved Unpredictable Fighter
Your movement increases by 10 feet.
Additionally, as a bonus action on your turn, you can make an Acrobatics check (DC 15) to gain advantage on your next round of attacks. If you fail the Acrobatics check, you make your attacks as normal, but attacks against you have advantage until the start of your next turn.

Level 18
Improved Wolf's Blood Pact
When you are reduced to 0 hit points and not killed outright, you regain a number of hit points equal to your Con modifier x your fighter level. You regain the use of this feature after you finish a long rest.
Your weapons now deal an extra 2d6 radiant damage.

Level 27
Lord of Cinder
You channel the energy of the First Flame and become a Lord of Cinder. For 1 hour you gain the following benefits.
• Your attacks have a reach of 10 feet
• Your attacks deal 4d6 instead of 2d6 radiant damage
• You gain resistance to bludgeoning, piercing, and slashing damage
Once this hour is over, you suffer 2 levels of exhaustion. You recover from all of this exhaustion and regain the use of this feature when you complete a long rest.

Edit 1: typos
Edit 2: typo...
Edit 3: added edit info.