Alchemy Student
x1
1
Argenport Blueprints
x4
1
Sinister Rumors
x4
1
Spitefeeder
x2
1
Toxic Wisp
x1
1
Zido, Cabal Housecat
x4
2
Copperhall Porter
x4
2
Devour
x4
2
Dreamsnatcher
x4
2
Usury Writer
x4
3
Slay
x2
3
Vara's Authority
x4
5
Crownwatch Press-Gang
x4
5
Harsh Rule
x4
6
Solitude
x4
Justice Sigil
x8
Shadow Sigil
x9
Argenport Banner
x4
Seat of Vengeance
x4
View Deck on Shiftstoned
If you're still interested, I think heartstopper always has been and always will be a trap for mill decks. The value it provided was too random and especially way too slow. You really don't have enough time to grind with him, he's to expensive, too weak for beat down or trading, removal magnet and if you get to draw a card with him, it's more often than not a sigil you don't need or a card you have no synergy with since the rest of the deck is so focused on the mill aspect. Never cared for it much honestly.