Definitely Castle. Rezona is mainly an ai app which I'd say sucks the fun and creativity out of game making. I don't like generative ai in general, and coding in castle already isn't really challenging, so I feel like anyone could grasp how it works. Castle has used some ai, but it either has just been beta testing (Guide and Operator), which don't play a major role in creating decks and I'm pretty sure they decided to stop using generative ai on their YouTube channel
Castle because Castle is life, life is castle, Castle is amazing we should build a cult around Castle where we make and play, Castle because Castle is cool, Castle because I dont know what Rezona is and I actually dont care either, Castle, Castle is better, Castle is better because nothing beats Castle, Castle is the best