The same counts for Loki as well, you know? This guy damaged Harald to the point he regained his consciousness back. The same Loki has 0 DF experience and was already exhausted after fighting with Ragnir - a weapon which even Harald was highly cautious about.
Idk how Shanks captured Harald but Oda better makes it very convincing by giving Shanks some huge Haki Susanoo powers lol.