I mean the one who inspired Luffy is a Swordsman, the Previous Pirate King whom Luffy strive to become like was also a Swordsman, and Luffy was trained for 2 Years by a Swordsman & this entire Wano War happened to finish what a Swordsman started, and Luffy's Strongest Recruit is a Swordsman & only WSS is currently Alive, Undefeated & in his Prime among those with "Strongest" Title, and both Strongest Nation overall & Strongest Human Nation have Swords as their Symbol ... etc
Swordsmanship + Haki is what forges Strongest Warrior
So imagine when your Swordsmanship is so great that you wield Three Swords unlike any Swordsman "Ever"
And your Willpower is so overwhelming that it visualizes as a Trion Demonic Spirit
Some Readers will never accept this Reality, it hurts them