He did appear in a hood and somehow snuck his way into the Goroseis chambers directly too. We know they're top tiers now too, so its even a MUCH bigger and crazier feat by him in hindsight, not to mention all the Holy Knights around and thus his relative Garling too ofc!
People wearing hooded cloaks tends to symbolise with cults and thus satanic rituals too, coincidence? Maybe thats why Shanks' anger has been described as so utterly unstoppable, terrifying and such? Because it's truly hellish in wrath? The devils fury incarnate?
Also Brook is from the West Blue like Shanks and Robin, Robin who has been depicted as a literal demon/succubus/devil whatever lately and been called a demon child for most of her life and during the timeskip, a cult tried to summon the Devil and got Brook instead! Brook became able to tap into the literal underworld through his devil fruit after this too!
Also from the West Blue we have Thriller Bark, Ohara, Kano Kuni, Lafitte, Jozu, Daz Bones, San Juan Wolf, Shanks ofc, Hina (no actual truly strong/powerful/important Marines though weirdly enough), Capone etc.
Things could get VERY interesting here and I'm sure they will ofc. Oda is heavily inspired by Journey to The West and the sun does rise in the east and sets in the west too, as someone else mentioned here earlier too ofc (Sun Luffy and Moon Shanks/Garling).
This guy has an AMAZING theory about Shanks, the Journey to The West influences on OP, West Blue etc too imo:
He also predicted Wano having time travel, Momo being aged up, Kanjuro being a traitor, all WAY before they happened canonically too!