Oda messed him up by not making him have a personal agenda but he can still somewhat save him by making him do dishonourable stuff for the greater good or whatever. Right now, he seems like a plot device that fixes everything wherever he goes.
Actually write him not fixing stuff for once and having flaws.
But yeah, in no world should Shanks logically beat Loki 1 on 1 with fair conditions. This would happen if Oda is a good writer. Only problem is Oda is absolutely garbage
Oda messed him up by writing him with zero character flaws. Saint Shanks is intelligent, brave, chivalrous, he literally has zero character flaws at all. And it’s completely unbelievable as Saint Shanks is literally just some smelly alcoholic but because Lolda is taking out his own insecurities on his manga, we have to sit and watch as Oda pretends a stinky virgin beta male crippled basement dwelling weakling is drowning in pussy and power. Lol
The only way Oda can redeem Saint Shanks is to make him explicitly and secretly evil, that is the only possible way to redeem him, because it would make all of his flawless character traits an intentional facade to conceal his own inner evil.
I’m pretty positive Oda is doing this as almost everything in Elbaph is setting up Saint Shanks being not who we think he is and hiding his true self.