So something like a drop shadow operation, but more complex
Originally, Regenerate was even tied to the damage prevention step, a now-obsolete part of the turn cycle where players could prevent damage or Regenerate them after damage had been assigned
Idolized does roughly the same thing, but costs a whole two mana less and counts every nonland permanent you control
This then allows you to save on shipping: 6 cards slipped into a card saver can still qualify for a regular letter in the UK (0.75 for 2nd Class), whereas 6 cards stored in 3 toploaders will require you to ship as a large letter (1.15 for 2nd Class)
There was a way to speed up the speed of the genocide king demon, which was inconvenient to use because of its slow speed, but since the added demon support cards don't fit very well with the chess demon, I made a deck based on the chess demon