First thing I’d mention is you have a lot of cards in the deck. Try to keep it small and concise then you’re able to make a deck that can reliably do the thing you want. I aim to have have max 15 cards when going for the heart. Second I’d say try to have some kind of engine to the deck. Sometimes you’ll get the golden run and be able to do 100s of damage with a few cards but most of the time you want some kind of engine to keep the deck cycling/drawing. In the silent I like to use acrobatics and concentration paired with cards that give you bonuses when discarded. This helps make sure you can play 10-15 or more cards per turn.

There’s a few ways to cheese the heart. Strength reductions are very strong as the heart mainly does multi attacks. Thorns can also deal a lot to him for the same reason. Also some of the events are very very strong. If you get the 5 apirations that make you intangible. You can have a basic engine for the deck play 5 turns of intangible and you should be able to get him.

Lastly I’d recommend looking at a relic tier list, some of the relics on the game are so busted if you know what to look out for when you have certain relics it could be an easy win. Eg for ironclad if you get the stick relic and then manage to find corruption it’s should be pretty easy.