u/leamh__

As I was reading Modulo and the plot of Yuji getting the "curse of immortality treatment™" I thought "why Yuji didn't make a binding vow to give his lifespan for something",that got me thinking on what are the limits you can offer on a binding vow,you can make a vow between two people and offer a service in exchange of something (Sukuna bringing back Yuta,Mahito improving Mechamaru's body),you can just offer a service to someone without gaining anything specific more like a pledge(Yuta with the higher ups to Kill Yuji), you can offer a disadvantage for you to gain an improvement in another angle(revealing your hand, Sukuna's shenanigans) and you can even sacrifice more nebulous stuff like never using a sword like Miwa...why not lifespan?

And with the new extras of Modulo with the Ui Ui stuff of syphoning life force from his students it kinda gives more force to the argument of life force/span being able to interact with normal sorcery without a specific CT.

PD:Even if I'm right I wouldn't count this as a plothole or anything,it just makes Yuji's character and his relationship with his long life more interesting because it is not a thing that happened to him without knowing and had to just cope,his sense of responsibility is ultimately the thing that kept him from happiness and would tie in with JJK being a tragedy.