I went with a probably-too-complicated Science Grant / Inheritance variant
Breakthrough PP Event
Move your Alembic token to an Aqua Vitae card with no tokens on it. (During your turn Potions are also Actions with 'If it's your Action phase, play the card with your Alembic token on it.')
Breakthrough (randomizer)
(Draw another randomizer)
Set Up:
Include the "Breakthrough" Event in the Kingdom.
Shuffle the Aqua Vitae Actions and place one per player, plus one extra, next to the Breakthrough Event; These are not in the Supply.
Return the rest to the box.
Important differences from Inheritance:
You can buy this multiple times, to change what your Potions do
You can still play Potion during your Buy phase for (Potion currency)
You have to pick an Aqua Vitae action that doesn't have a token on it, so your potions can't do the same thing as other players potions. (This is how it qualifies for the contest.)
You'll only have players+1 Aqua Vitae actions to choose from, so these won't all be available every game
The setup instructions are on a randomizer (like castles) since the event itself was already super crowded; the randomizer tells you to draw another randomizer since you'd be down a pile otherwise.
I made up nine "Aqua Vitae" actions - they aren't as important as the event itself but they're all roughly a "Strong 5"; I'd consider these more "thoughts about where to go with Aqua Vitae actions" rather than "these are the Aqua Vitae actions, fullstop"; they probably aren't balanced currently.
My guidelines for Aqua Vitae actions are:
no "incredibly unique" cards - there's a fair bit of functional overlap with these
no durations - too hard to track
worth roughly $5
mostly non-terminal or remodel variants
Transfigure $5 Action - Aqua Vitae
Trash a non-Victory card to gain a card that shares a type with it.
a remodel variant; can mill Curses but not trash them outright (until the Curse pile is gone). Can remodel copper into Gold and ruins into princes.
Grimoire $5 Action - Aqua Vitae
+1 Action
You may play a Treasure other than Potion from your hand.
Draw until you have five cards in hand.
Nonterminal library variant. The restriction on Potion is because it's confusing enough when you play Crown with Storyteller. of course, you can play Crown->Potion with this, which is its own can of worms but i figure that's niche enough that anyone who does that wants the complexity.
Radiant City $5 Action - Aqua Vitae
+2 Cards
+2 Actions
At the start of your Buy Phase, you may discard a Potion for +$1 per unspent Action (not Action Card).
"Diadem Village"
Oust $5 Action - Aqua Vitae
+2 Cards
+1 Action
Reveal the top card of your deck; you may Exile it or put it back.
dejunker that works a little smoother than native village, which is a trap card
Trestle $5 Action - Aqua Vitae
+1 Buy
Cards cost $1 less this turn.
You may reveal a card from your hand that you do not have a copy of in play for +$2.
potentially better bridge.
Agistment $5 Action - Aqua Vitae
+2 Cards
+1 Action
If you have an odd number of Potions in play, +1 Card.
Stables/Lab variant.
Symposium $5 Action - Aqua Vitae
+4 Cards
+1 Action
+1 Buy
Discard 3 cards from your hand.
Stronger Forum.
Abyss $5 Action - Aqua Vitae
Trash a card from your hand. Choose one:
Gain a card costing up to $4; or
Gain a card costing up to $1 per uniquely named card in the trash, and if the gained card was a Victory card, trash all Potions you have in play.
revised this to remove the early dud-ing.
Repair $5 Action - Aqua Vitae
+2 Cards
Trash a card from your hand to gain a card costing up to $2 more than it.
If both cards share a type, +$2.
revised this to be slightly better than remodel
and then these are the Alembic tokens I quickly threw together; they're adventure tokens; i used the windows segoe emoji font with the 'alembic' emoji for the icon.