Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
It's just that Luffy's persistence and ability to learn through battles are much more astounding than Crocodile's fighting prowess.
Source: https://www.cbr.com/one-piece-crocodile-earned-warlord-title-shichibukai/