1. It's established at the beginning that Sukuna can replicate anything at first sight as long he can do it
2. Sukuna is constantly asking Mahoraga to show him something he can do (234)
3. There's a ton of other more subtle clues
If only we actually got to see the finale lol
This time, things get back to normal.
Put JJK spoilers in the wrong thread, it will be over for you faster than it was for Gojo.