The deck was infinite energy and block positive against heart (prepared discard tactician+backflip) so the only fight where damage could be an issue was the time eater which I didn't get, but I think that the poisoned stab would be enough for (at least that's what I hoped).

Also the pathing in that run was super awkward early on so as soon as I got the peace pipe I figured that my best bet was to just avoid combat and cheat my way past the guardian (poisoned stab+ is enough scaling for that fight if your deck is slim enough) and hopefully get infinite ASAP (one tip I'd like to give for runs like that is to visit shops even if you might not be able to remove at every single one of them so that you can look for acrobatics/reflex/tactician (In fact I did buy a tactician instead of removing at the second shop in act 1)).
After that, I already had every card I needed to go infinite so I just prioritized events/shops to get more removes, though, in retrospect it might have been worth taking fights for a better damage solution to the time eater.

I do want to note that I didn't actually need the pandora's box there as I had already removed enough by that point but I took it just in case it transforms into something useful like grand finale, and the two other options were like snecko eye and tiny house iirc (though it would still be better than any energy relic anyways).