Dive into your creative stream
It's time for me to do something. Let's start with this page, aka one of the only times we see Sukuna mention Tengen directly in the manga. We see him eating his old body, which is now a shinbutsu mummy. This state is achieved only via *extreme* fasting which will keep the body-
what's the takeaway here
We know that Sukuna should have been a twin, but was forced to eat him to survive due to starvation from his mother's womb. My theory is that Tengen is Sukuna's mother, which is exactly why he called the act of eating his old body that Tengen had conserved with her ironic
He was eating "Himself" because of her again, and not only that the "himself" in question was left in a state of extreme starvation, tying in to the first time again. Imo, this scene, is Tengen expressing desire to feel close to her son, even just by looking like him, because
-she couldn't give him even a smidge of the motherly love he should've had due to her being deeply plunged in her isolation and buddhist practices, only idly watching the world unfold, which deeply infuriates activists like Kenjaku and Tsukumo Yuki
And what Sukuna undergone before being born was akin a gu ritual, and the Culling Game is like a gu ritual too, where the strongest survives
"With this theory in mind it gives another layer of poetry to Yuji and Sukuna. Both were abnormal due to their mothers, both were too strong to relate to others, both bear the spiral of curses in their eyes yet the path they chose were fundamentally different"