In order for the effect to be maintained, it would be necessary for it to end explicitly in the End Step, just like Final Fortune, which despite talking about the end of the turn had an errata in its text adapting it to the End Step, allowing you to use the card along with Obeka, Brute Chronologist to gain extra turns before losing the game
Ruin Rat Most rats are great expendable creatures, and Ruin Rat is proof of it
Instants and Sorceries Using instants and sorceries gives your deck a lot of flexibility with a mix of removal spells, card draw and tutors, as well as combat tricks and protection spells
Your strategy here consists of playing as many cards as you can from exile to create a lot of Treasure and generate some strong mana advantage to play even more cards
Instead theyre randomly selected from the previous 5 expansions: Rise of the Floodborn, Into the Inklands, Ursulas Return, Shimmering Skies, and Azurite Sea