Ace's history page says he had defeated Hanafuda after becoming WB's subordinate, but he was invited to join as a Warlord before meeting Whitebeard, so that's impossible as all the spots were occupied.
Hanafuda was a Warlord before the story began Oda revealed in the SBS. He was a smuggler of Ancient Zoans who probably supplied Kaido with a lot of his but the Kaido connection isn't flat out stated. After Hanafuda died Ace was offered a slot but denied it, getting filled by one of the 7 we knew when the story started. I don't think we ever find out who but people smarter than me can probably figure that out
