Man, this is such a good idea. Becoming a seer overtime would be so much fun for a player, especially if they seek counsel of other seers in the process and witness how myths unfold instead of necessarily intervening in them. It definitely requires the player to play along as more of a side character, but for me personally, that's the exact kind of character I enjoy playing. It enables players to really be the ominous person that the fellow Knights turn to for very specific solutions / advice (like a seer!) like the "drown" passion paired with the ability to breathe underwater. I like a secondary idea of rolling up a base game (or other homebrew seer) either at the start or end of your Sight to imagine what sort of seer you'd end up becoming. It would be super fun, especially when the seer you have rolled might be very different from the base Apprentice you are, so you get to think up how you change from one to the next, or potentially choose a fitting one (like the Reed Seer for the Fish Reek). The constantly shifting paths that your character brings to the party is also a brilliantly simple idea. It really makes your character mysterious and miraculously appearing like a Gandalf or Merlin character for sure, while making for a great randomized utility that shows your character knows their way around the realm, even when it resets.