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.