mystical is unlocked by an event upgrade using essence, gained overtime by discovered potions. Potion shelf upgrade specifically.
Awesome thanks for info. Apparently essence gain is just so slow (or rng from what potions you acquire/ingredients you gain/magic generation), you can't tell what these upgrades need or do before event runs out.
I did unlock events while in the middle of night event so for 2 weeks I didn't know anything about topaz etc except for this chat. Extremely confusing without some notes to say as much. Appreciate
It would appear based on how strong the bonuses are with mystifier and bundle, that not having topaz to use on event (or generating in background?) is a pretty big disadvantage to expected speed of essence gain and ability to gain everything. This would make my experience far less impactful than it should be if topaz is balanced into the speed of play.