Chase items, practical collectibles

The game would greatly benefit from chase items, tangible "Legends" and achievemnts that are more than some fancy text in an obscure challenge menu nobody ever looks into.

The Setting gives prime opportunity for clues, rumors, visual storytelling and sidequests to lead to unique rewards that can be looked and or maybe even used by the players. Like the Excalibur as a heavily enchanted magic sword that can be wielded by players after doing a sequence of tasks to actually locate and become worthy of wielding it. A trail of failed philosophers stones that appear in semi-random locations alongside scattered diary entries leading perceptive players to the final resting place of an alchemist who managed to create the real Philosopher stone at the cost of his own life, giving players a powerful unique augment station that can only be placed once per player.
A single Unicorn, roaming the realms for every player to be interacted with exactly once, giving them a unique tale to tell, maybe a souvenir if the interaction goes by peacefully or a mountable Trophy if the Player does what humans do best.

Those are just a few examples I came up with with a bit of brainstorming, the potential items and experiences are endless and can be anything from extremely obscure to somewhat easy to find, simply to keep players interested in exploring and spreading rumors among themselves for those unique rewards that are not as easy to even find out they are in the game. Because as of right now, the game becomes very dull very quick once the pool of quests has been fished dry with meaningful endgame potentially being months or years away.