The TCB trans is wrong, the 生まれながらに makes it clear that Yuji had a finger sealed in him on birth. The translation is from Bergelmir on fanverse, for Sakunas and Uraume can be seen below.
This is confirmed by volume 14 cover where only 14 fingers are despite the fact Yuji had already consumed 15 fingers making it only a total of 19 fingers
Page 1
Uraume: Who and what is Itadori Yuji?
Sukuna: He is Kenjaku's child. Of which body, I don't know.
Uraume: ....That time, I was sure I felt something just like Sukuna-sama did.
--------This could also be "I was sure I felt something like Sukuna-sama", as in Uraume felt the same thing in Yuji as he feels in Sukuna-sama. Which. Totally valid interpretation since they're talking about Yuji having a soul-relation to Sukuna.
Uraume: But I just made a show of laughing
Uraume: Its exceeding power cannot be explained by just the traces of Sukuna-sama's power left in a empty vessel
Sukuna: Its Kenjaku. There is no way he would have a child without a reason
Sukuna: Most likely, the one he joined with is the reincarnation of my other self
--------番った相手tsugatta aite is the 'the person you/he/she/they paired with', can be used as a lab partner, a sports partner, any partner. And a marriage partner, a sexual partner. Sukuna is just saying "the person he got dicked by".
Sukuna: I believe its soul was the same
Uraume: Sukuna-sama's other self.... you say?
Sukuna: I avoided my destiny to be born as a twin
Sukuna: My mother must have been starving. So before I began starving as well, I ate my other self inside the womb.
Sukuna: And his soul spun and spun and paired up with Kenjaku.
--------巡りmeguri is to travel, patrol, go in circles. Its also a word used to describe people/souls reincarnating through time. So he's saying the twin reincarnated over the millenia until, as Jin, it made sweet, sweet love to Kenjaku.
Page 2
Sukuna: Just like you know, Itadori Yuji was
Sukuna: born as Player of the Culling Games, and had my cursed item sealed in him.
--------So this is the line in question. The word 生まれながらにumarenagarani means "while being born, as he/she/they were being born, when born", and it is grammarly situated to link to both being a Player and having a finger sealed in him. Meaning that Yuji was both already a Player and had a finger in him when he was born.
Sukuna: It was probably to ensure his strength as a vessel
Uraume: I see....
Uraume thoughts: But, then....
Uraume thoughts: Does that not mean that Itadori Yuji has potential hidden in him equal to Sukuna-sama.....?
--------潜在能力senzai nouryoku is 'potential, potential abilities/capabilities, latent abilities/capabilities'. Basically all the latent potential a person has.
Take it as you will.
Uraume: Who and what is Itadori Yuji?
Sukuna: He is Kenjaku's child. Of which body, I don't know.
Uraume: ....That time, I was sure I felt something just like Sukuna-sama did.
--------This could also be "I was sure I felt something like Sukuna-sama", as in Uraume felt the same thing in Yuji as he feels in Sukuna-sama. Which. Totally valid interpretation since they're talking about Yuji having a soul-relation to Sukuna.
Uraume: But I just made a show of laughing
Uraume: Its exceeding power cannot be explained by just the traces of Sukuna-sama's power left in a empty vessel
Sukuna: Its Kenjaku. There is no way he would have a child without a reason
Sukuna: Most likely, the one he joined with is the reincarnation of my other self
--------番った相手tsugatta aite is the 'the person you/he/she/they paired with', can be used as a lab partner, a sports partner, any partner. And a marriage partner, a sexual partner. Sukuna is just saying "the person he got dicked by".
Sukuna: I believe its soul was the same
Uraume: Sukuna-sama's other self.... you say?
Sukuna: I avoided my destiny to be born as a twin
Sukuna: My mother must have been starving. So before I began starving as well, I ate my other self inside the womb.
Sukuna: And his soul spun and spun and paired up with Kenjaku.
--------巡りmeguri is to travel, patrol, go in circles. Its also a word used to describe people/souls reincarnating through time. So he's saying the twin reincarnated over the millenia until, as Jin, it made sweet, sweet love to Kenjaku.
Page 2
Sukuna: Just like you know, Itadori Yuji was
Sukuna: born as Player of the Culling Games, and had my cursed item sealed in him.
--------So this is the line in question. The word 生まれながらにumarenagarani means "while being born, as he/she/they were being born, when born", and it is grammarly situated to link to both being a Player and having a finger sealed in him. Meaning that Yuji was both already a Player and had a finger in him when he was born.
Sukuna: It was probably to ensure his strength as a vessel
Uraume: I see....
Uraume thoughts: But, then....
Uraume thoughts: Does that not mean that Itadori Yuji has potential hidden in him equal to Sukuna-sama.....?
--------潜在能力senzai nouryoku is 'potential, potential abilities/capabilities, latent abilities/capabilities'. Basically all the latent potential a person has.
Take it as you will.
This is confirmed by volume 14 cover where only 14 fingers are despite the fact Yuji had already consumed 15 fingers making it only a total of 19 fingers
