While the outshine Luffy is a genuine issue considering how much Oda loves his MC, Luffy did get portrayed to be clearly superior to Saturn in the previous chapter, with Luffy blocking all of Saturn hits while using him as a training dummy for Bonney to train her punch, Luffy his above his paygrade and the issue comes from the immortality hax
I still don’t see Saturn surviving this arc for plenty of reasons I listed in another thread , and it happens Kizaru is the most likely candidate left as he should (I say should because we know with Lolda) have a closure to his arc.
Although if Saturn were to die, it’d be because for x reason the immortality would be off.
We should be fixed next chapter anyway