1. A dark UI
2. Maybe yes
3. Yes, you can also use the web version
4. Maybe late 2026 or early 2027
5. Using HTML's iframing. Though some websites block it
Also one thing, they imported through websim/websites by adding link URL to Cauldron AI to make them turning into an emulator which is like how cloud gaming work.
Cauldron is like AI chat to generate decks They used different stuff that is not on castle such as 3D, Full colors.
It's located in chat settings in your project like between Guide and Operator.
It will release in late 2026 to public, but this is just prediction because Cauldron is still developing and early access to only smart people that is good on making games by complex things
Yes iPad will be compatible also, all across devices.
Since I'm not a castle tester, I don't know what cauldron really looked like.