Tower Guild: Puzzle Cards

I wasn't fully enjoying it at the start but it grew on me a little. I felt pretty weak. You start with 1 character in a run balanced for 3. You Harvest some materials and then get to town, and spend them on getting the second character. Now you can choose a slightly altered beginning loadout by swapping who is in front and get a different starting card from that characters pool of cards. Eventually after some failed runs you get enough materials to unlock the 3rd character, now the runs feel more balanced because you get 3 cards to start with and 3 characters to take damage instead of 1 or 2. But... I have one issue with this 3 character system. If 1 dies, its Game Over. I hate this. This right here almost made me refund after I was fighting a Mushroom boss and he was literally 1 turn away from dying and so was my frontline character. But I've come to acknowledge that it is what it is... Unless? Anyways, the game was starting to stagnate for me. The next character unlocks show whats needed for materials to unlock them but they're all higher grade stuff im not seeing drop yet. My characters were still weak so I was looking into what materials i'd need to power up my card…