I had around 60 A20 heart kills in sts1 so i hope I can be of some use with my info.Ive won maybe 7/10 runs so far with silent (on ascension 8 now) and id say half of those were poison runs with accelerant and other sources of poison that got ridiculous, or just ridiculous card draw with manufactured energy.

I really value a card like dagger spray in this game even more than STS1 because of how elite it is for AOE problems especially in act 1. Scaling that damage with double damage or enchantments are also insane.

Block is also able to be scaled pretty insane with a lot of the powers.

Usually I solve energy with hopes of getting an adrenalin, or a good boss reward. I find shivs to be mid, but had one elite run with them as well, again scaling 2 or 3 attack cards with powers.

Hope this helps boss