If people are really so desperate for making unique characters... you'd all be better off doing it the easiest way-- by the character's personality and how you roleplay it. Rather than waiting for someone to write a book that throws in a couple game mechanics to theoretically do it.
I mean... here is what your PC gains
mechanically to make them "unique" when they take one of the Paths n this latest UA...
4th level:
INT/WIS or CHA +1
+1d6 + MOD on next attack after someone is reduced to 0 HP
8th level:
INT/WIS or CHA +1
recover 4 levels of spell slots once per short or long rest
OR
INT/WIS or CHA +1
ally gains Temp HP
OR
INT/WIS or CHA +1
gain cantrip and use spell slot to add 1d10 necrotic damage per spell slot and CON save to avoid Paralyzed
12th level:
INT/WIS or CHA +1
Type becomes Undead, resistance to Necrotic and Poison damage, no Exhaustion levels for certain things
gain spell and always have it prepared-- cast it modifier times per long rest without spell slot
self-resurrection in 1d10 days
So your so-called "unique" PC is gaining bonuses to INT, WIS, or CHA... the same bonuses that any other character can also get when choosing a feat. They are also potentially regaining spell slots just like almost every spellcasting class already can do. They maybe are giving out Temporary Hit Points-- a mechanic that is seen countless times across the entire game. Or making a single cantrip more powerful and adding a rider on it to give the Paralyzed condition to someone... an ability that is already given out numerous other ways in the game (either Paralyzed itself or even more powerful conditions that render a creature helpless) via all manner of other spells or abilities. And finally you can gain Resistance to two energies at 12th level or above that many other PCs already had back at like 1st, 2nd or 3rd level, a free spell PCs can already take without this feat and you can get resurrected from being dead just like probably every PC was already getting back at 5th level when the Cleric took
Revivify as a spell.
So what exactly is "unique" here? As far as I can tell...
nothing. None of these mechanics are unique. They are the same mechanics given out to PCs at any number of different levels across the board. So these feat chains are not some grand bonus to character originality that makes your PC a special snowflake... they are just alternate ways for characters to gain mechanics at different levels and in different groups that everyone can already get. Game mechanics do not make your PC unique because it uses the exact same mechanics dozens of times across dozens of different options. I mean heck... how many times do we see "gain X skill" or "gain Advantage on next attack roll" for all of these classes, subclasses, feats, features etc. etc. etc. in an attempt to make us think we are getting something cool and unusual? All the time!
But do you know what is TRULY unique? What is actually different when they make all of these new abilities and things in all these books and UAs? It's the
flavor they put on top of them. The truly unique thing is the
story that defines these abilities and tries to fool us in thinking they are actually different. THIS ability is your PC making a Vow as part of their oath to see their hated rival defeated for what they had done to you... while THAT ability is your PC getting so riled up and bloodthirsty in combat that you just overpower your foes as you swing your weapon savagely. Both abilities define how your PC "behaves" within the story of the game and how you as a player roleplay your PC as a part of that story. Your two characters are different and react differently and behave differently... all because of the flavor that is given to you by the game designers to inspire you to roleplay differently.
Meanwhile... mechanically both of them give you Advantage on your attack. The exact same mechanic for two "different" abilities.
So why are they different? Because you as a
roleplaying game player... roleplay your character using that ability differently. One might say "uniquely". The roleplay of the ability is what makes your character unique. How you roleplay in general makes your character unique. And believe it or not... you can roleplay your character as a unique character while not having a single game mechanic that is different than anyone else. Your PC wildly swinging a battleaxe in the narrative of combat is roleplayed by you differently than that player making very grand slashes and parries with their longsword, even though they are both doing 1d8 damage.
And once you can accept that... that you can make a unique character just by how you roleplay them... you no longer need or care the manner in which WotC decides to bundle all these repeating game mechanics into new groups. And whether they get called "subclasses" or "feat chains" or "prestige classes" or any other term that gets tossed out to try and fool you into thinking this ability that gives you a +2 to your AC is somehow different than all the other abilities in the game that can grant you a bonus to your Armor Class.
Come over to the light side! Let go of mechanics and embrace story! You will be much happier and find things much more "unique" when you do!