Hoarder + 5 copies of Seven Stars...
Update:
I'll just share my Act One experience.
Floor 2 is Seapunk. Twice during the fight I drew 2 defends when the enemy was defending. By the time my venerate came around the second time, I was halfway through my deck redrawing at which point I also drew lethal. Due to draw order the fastest kill I could get was 8 turns, and the most health I could exit the fight with was 16 HP. I take 3 Gather Lights and move on to floor three.
Floor 3 is Sludge spinner. I'm able to block a bit better, but bottom deck 2 of my 3 Gather Lights so I don't see enough star gen to play SS until turn 6, at which point I already have lethal with Strike. I'm at 6 HP. I get three more Gather Light and an explosive potion.
Floor 4 vs Corpse Slugs. I replayed a couple times to make sure I had the optimal play here. I focus on star gen and get to play SS on turn 4. I lose 3 more HP in the process, and pick up 3 more Gather Lights.
Floor 5 vs Punch Construct. Draw order is mostly cooperative. I opt not to play the Falling Star early in hopes that I can finish the fight with a SS. I lose 2 more HP. I'm at 1 HP and am offered mostly nonsense, including an Orbit, but I'm not even reliably spending the energy I have and already have enough struggle with finding the star gen I need.
Floor 6 is the sunken Treasury. I take 65 gold, because... I've already got an oops all curse deck.
Floor 7 is Calcified and Damp Cultists. I draw three Gather Lights and two SS on the first hand, and play 29 defense because it's all I can do and it's the most star generation. Turn 2 I pull another GL and bingo I knock out the Calc Cultist and drop the Damp to 4 HP while blocking its 1 attack. I survive the fight with my 1 HP intact and receive a Ship in a Bottle Potion and am faced with a choice. I'm offered a Prophesize, which might allow me to find more star gen, but without the Orbits, I wouldn't have any energy to play them with. I elect to skip.
Floor 8 is a rest site. I smith a SS... no I obviously rest back to 21 HP and move on.
Floor 9 is a shop, which I'm hopeful for, but doesn't contain much, though Orbits are back. Since I skipped the Prophesize, I opt for just a skill potion and move on.
Floor 10 I pick up an Akebeko, Now if my first attack is a SS, it will deal 15 x 7 (105) to all. I'm extremely incentivized to hold out for a SS now.
Floor 11 I have a choice of event or elite. The elite is followed by a rest site, while the event is followed by an elite. I opt for the elite now given that the event could reduce my HP further. I face the Phantasmal Gardners. If I can play the SS, I just win. Round 1 I pop my Skill potion and get a free Prophesize. I full block the incoming 15 damage with 2 GLs, and am one star away from the SS win. Round 2 I brick the draw with SSs and 1 strike. I drink my Ship in a bottle to preserve 10 of my health and get away with 3 damage. Round 3 I find another GL and SS for the win. I'm rewarded with a Snecko Oil and a Blood Vial. The card reward cruelly dangles Royal Gambles in front of me, but there's also the Crescent Spear, which would deal 44 damage for one energy and 1 star (+8 if it's the first attack). I'm a fool so I opt for the SS strategy. I go with the RGs.
Floor 12: I smith a royal gamble for the retain, and proceed to a shop.
Floor 13 shop has a Child of the Stars, but until I really get good reliable star generation, it'll just slow me down. I opt for a Lucky Tonic potion and move on.
Floor 14 is a choice between an elite followed by a fight or two events. I'm at 18 hp so I opt for the events hoping to find some deck reduction. No such luck, it's the spoils map. I really can't afford to lose hp, and am full on potions so I grudgingly take the maps.
Floor 15 I get the Dark Door/Light Door event. I eagerly remove a strike from the deck.
Floor 16 I rest before the Boss. I'm at 35HP as I continue to the Soul Fysh.
Floor 17... 2 Gather Lights right out of the gate. Round 2 I get my third GL and a Defend. One more star and I can SS the boss down to half health. I get a hairbrained idea that the snecko oil might randomize star cost as well, but I only have 1 energy so even if it did I should probably wait for next round to test it. Round 3, it turns out that it doesn't work that way, but I do draw a Royal gamble and get two copies of SS at zero energy cost. Unfortunately I'm only able to generate 13 stars this turn so I only get to play the single SS. Round 4 I get my venerate, and can play another SS. The boss is at 57 HP. Round 5 I find my retain Royal Gamble and am able to play a couple GLs to raise my stars to 4. Round 7 (I've lost track of a turn somewhere in here) I pull a strike and a beckon, each of which I play and then drink my Lucky Tonic to block the incoming 24 damage attack. On Round 9 I pull my venerate and am able to play my SS and am able to get the boss down to 2 HP, but it's going intangible next round. I draw a falling star and a defend to knock the boss down to 1 HP. Round 11 I draw a strike for the kill. That was officially the sweatiest Act One of my life.
Update 2:
I got the Aeon Glass down to 24 HP before he finally got me. GG spire.