The full effects of the spell can be seen in the foreground, as its unfortunate victims dissolve into ash
You can find Eric Switzer's reveal on Twitter
As with many cycles, the early choices were easy and then it got more difficult
Its a Time Walk effect that shuffles itself into your deck, so with a bit of card selection and filtering, you can play it every single turn, or at least very often
This can vary depending on how rare the card is or demand for certain cards, but generally that is a good starting point
If a non-ongoing scheme card is face up in the command zone, and no triggered abilities of any scheme are on the stack or waiting to be put on the stack, that scheme card is turned face down and put on the bottom of its owners scheme deck the next time a player would receive priority