In a quick change of the fight, Sukuna took advantage by accumulating all his cursed energy in one of his fingers & forced Gojo to ingest it. Everyone got up including you when they saw what could be a new threat

Suddenly Gojo began to laugh exaggeratedly, wiping a small tear from his eye "Did you really think you could have control of my body? How naive" The voice changed to Sukuna's showing irritation "Tch, what a bother"

The fusion was complete. GoSu stood before them, a being of unparalleled, intellect & cunningness, the perfect amalgamation of Gojo’s boundless potential & exceptional tactical & adaptable intellect and Sukuna’s malevolent force & cunningness. The air crackled with cursed energy, and the very ground trembled in anticipation of GoSu’s next move.

GoSu: “So… (both Gojo’s & Sukuna’s voice) … it seems we’ve reached a compromise.” His smirk is just like Gojo’s iconic smirk with Sukuna’s iconic arrogance.

He quickly made numerous binding vows, many of which are unrevealed to his opponent. A very clever, cunning, 5D-chess, galaxy-brained being.

GoSu: “Heh, what do you know about binding vows? They can be quite useful” GoSu smirks, mischievously

[Due to his galaxy-brain (meme), GoSu likely has multiple incomprehensible, nonsensical, stupidly absurd, convoluted layers of these binding vows pre-prepped (like he’s Batman) for any situation. The more severe the limitation, the greater the power boost. The sheer unpredictability of his Binding Vows makes GoSu an overwhelming force. He’s like a 5000 IQ galaxy-brained GigaChad.]

GoSu: ”Checkmate noob” He mockingly said like Gojo. “I made a binding vow unto myself known as Galaxy-Brained. It goes beyond just being "smart", becoming an intellectual force of nature. I can instantly outsmart and outwit anyone in my path, always make the right decision while avoiding all errors & failures.”

He playfully smirks

[His ”Living Hax” (all haxes) binding vow is also in play.]