Got the Assassin System, But it was the Demoness Pathway [An LotM Fic]

That time when I got isekai'd into the body of an Assassin Pathway boatswain of Vice Admiral 'Ailment' Tracy, and got the Assassin System. Clearly, there was only one thing for me to do, digest the potions, and switch to Iron Blooded Knight of the Red Priest Pathway as soon as possible. Everything that happened in between is just a story to tell. There will be pirate hunting. __________ There will be lots of spoilers here, for LotM and COI both. __________ No AI slop. Never will be.