I forget a bunch of what this card was meant to be.

This came up in discussion of Thawing Glaciers's Oracle wording. (I remembered the old errata saying something like "If it's the end step, return ~ to its owner's hand. Otherwise, return ~ to its owner's hand at end of turn." It turns out they've found a more sensible wording, "At the beginning of the next cleanup step", which is pretty weird but better than what it was before.)

Vitenka mocked Oracle as he does ;) and proposed this card. I smiled and commented how much it'd do, for something that looks like it should do nothing. (I think the proposed card was an enchantment, not a sorcery, FWIW.)

Thinking it through in more detail, it's not quite as absurd as I thought, but it's still pretty interesting. It doesn't prevent cleanup, as Time Stop's reminder text shows. (Though it would prevent Thawing Glaciers from returning to your hand.) But what it does do is prevent many other "at end of turn" / "at the beginning of the end step" triggers from happening.

More precisely, assuming this is an enchantment: all your opponents' EOT triggers still happen during your turn, but you can choose which of your EOT triggers get to happen and which don't. On opponents' turns, none of theirs happen, and again you can choose which of yours do and which don't. So you can choose to keep your Ball Lightnings and Arachnus Webs alive as long as you want, your copies from Heat Shimmer and Minion Reflector don't go away and nor do your Pestilence and Mark of the Oni, Thran Quarry and Glimmervoid become Utopias, and Suppress becomes Wit's End.

Come to think of it maybe "skip your end step" would be a more workable version of Staying Power. (It doesn't make giant growth permanent, but it does for the things alex listed)

Reminiscent of Sundial of the Infinite, in regards to some of the things this can do.