The Soul's Ferryman

you made a pact with an entity that  gave you the task of transporting souls to a specific place, plane of existence or time, the entity can be of any nature, even divine, and this pact gives you the ability to manipulate souls to accomplish this mission

Souls Harvest

as a reaction, you can collect the soul of one type of creature, that u choose when u take this feature and u can't change it(humanoid, fiend, beast, fey...), that has been dead for less than 1h and store it in a cage that you carry on you that can contain only one soul, u get more souls cage at lvl 3,6,10,14, for every cage that has a soul inside, you can choose one more skills proficiency , in addition you can choose for each ability check to add 1d4  , however every time you choose to add the d4 you must roll 1d20, if the result of the d20 is lower than the result of the d4 the soul is freed. If you have more than one full cage you can add 1d4 more per cage, but if the d 20 rolled next is lower than the sum of the d4 rolled you will lose souls based on how many cages you chose to use, for example if you use 3 cages to add 3d4 to an ability check and you get an 8 and the d20 roll is a 4 you will lose the souls in the 3 cages you chose to use, along with the proficiency you added. You can harvest a soul a number of time equal to half of you proficiency, rounded down (minimum of 1) 

Souls Attunement

 your patron, given your familiarity with souls, has granted you the power to draw on their essence,once per long rest you spend your move action to channel the power of one of your soul adsorbing it, then  you can use the effects of the Soul Cage spell on the activated soul , up to a maximum of 2 times, once the two options are used or after 8 hours since absorption of the soul, the soul is freed, losing one of the proficiency acquired by the soul harvest feat.

At lvl 9th u can adsorb up to 2 of you souls per long rest, and up to 3 souls at lvl 11th, every time u adsorb one of your soul you must spend your move action, but not to use the souls cage option.

If u take the spell soul cage with the Mystic Arcaneum feature, u can add these option to the soul cage spell :

-Soul burst: as a bonus action u can empower the next attack u made, you can add 1d6 necrotic damage for any damage u inflict to your enemy in this turn

-Soul armor:as a bonus action u can use the soul you harvest as a shield, you are behind half cover until the end of your next turn

-Soul foot: as a bonus action u can use the dash or disengage action

Rise out from the Cage

your patronus has granted you the art of soul manipulation, from 10th level, once at long rest you can summon the souls that reside there from your cages, making them take a shape more congenial to you up to 30min or you can use your souls to summon a creature of your choice that you have already met for 1in, this creature will have a cr equal to the number of souls you use to summon it, you can also choose to divide the cr into multiple beings so that the sum of the cr is always the number of souls that you have used with this feature, for example if you have 4 cages with souls and choose to use all 4 souls with this feature you can summon one monster with cr 4, 4 monsters with cr 1, two with cr 2 or two creature one with cr 1 and the other with cr 3, the summoned creatures must have a minimum cr of 1.
you can still choose to use the souls attunement feature on souls, when you choose to exploit souls when they are out of the cage using souls attunement they lose half of their HP/the cr of the summoned creature

Deconsecrated soil

your patron grants you the use of the souls present in the lower floors,starting at 14th level, once in long rest you can recall these souls by creating a deconsecrated ground of 60 ft in diameter where the souls roam free for 1min, every time you hit an enemy in this area he suffers Additional 1d8 necrotic damage, plus must succeed on a DEX saving throw or the souls will envelop the target, halving their movement speed and giving them disadvantage on next TPCs he made, in addiction if the souls of yor rise from the cage are in the deconsacrated soil and u hit a target, u can use your reaction to teleport  the souls in 5 feet of the target you hitted.