Sukuna having a keen eye when it comes to observing his enemies. Making note of Hana's feelings for Megumi (without her explicitly mentioning) and using it for his advantage in a dire situation. This can be also taken as another instance of his capability to comprehend emotions.
The duality and juxtaposition shown by Gege in Sukuna's personality is commendable. Honored one (Buddha reference) by the narrator and Fallen One (Satan)
Misinformation final boss
Sukuna didn't do any prep before his fight against Gojo.
GOJO was the one to ask for a delayed date. Sukuna was ready for all the smoke when he was at 16 fingers LOL