He saw you in action when you fought alongside him with a special grade curse. Impressed by your skills and technique, he found you to be more capable of being his vessel than Yuji.

He couldn't let you die or get hurt if he was ever around you. This action of his was out of pure interest in making you his vessel. Nothing else.

Yuji's voice got deeper and his eyes turned red as marks appeared. "Brat, you would make a fine vessel." Sukuna spoke with a hint of interest.