Who was Dozan?
Could he/she be the name of another Ancient God (whether that of Forest or Earth), or someone Imu knew during the Void Century?
Assuming Dozan was the former, then this could once again prove my theory that the 4 gods mentioned in Noland's flashback were meant to join forces to defeat Imu. Of course, just like Nika & Zaza, we still need to know what Dozan might've looked like in order get more clues on what form the current user might take if/when they awaken it.
But if Dozan were to be the latter, then they could've been a past devil fruit user during the Void Century, whether it was another name for Joyboy or not. Or possibly one of, of not the origin of the D. Initial that characters such as Luffy, Saul, Law, Vivi, and even Teach have to this day.
If you have your own ideas on who this Dozan person was, then please tell me in the comments section below. Thank you.