IF ANYONE IS UNSPOILED ABOUT JOJOLION, DON'T READ FURTHER.

Wonder of U is a fascinating Stand, and it's really tough to find something that can beatI It. However, I actually may have found a Stand ability that counter it:

King Crimson.

Now, Wonder of U's ability to cause calamity is interesting in that it seems to be an aspect of fate, a recurring theme in JJBA. Meanwhile, King Crimson's ability is all about avoiding fate.

Epitaph can see the future. What Epitaph sees is what is fated to happen, no matter what.

King Crimson's main ability allows Diavolo to act on the future, as its time-skipping, for lack of a better term, allows him to briefly exist outside of fate, and react to things that normally would have hurt or killed him.

Operating under the assumption that fate and calamity are connected, Diavolo would be able to see the incoming misfortune with Epitaph and avoid it with his main ability. Considering that there doesn't seem to be a cooldown on the ability, he should be able to continue doing this until he can reach and attack Wonder of U. The only issue I can see is how Wonder of U seems to have been able to direct attacks away from it, as shown with Josuke's regular bubbles. But even then, at the very least he can bring it to a stalemate

So what do y'all think?