Timestream Navigator

Repeatable extra turns are the most carefully gated effect in the game, and the cards that grant them pay for the privilege in obvious ways: Time Warp costs five, while designs like Magosi, the Waterveil and Meditate build in a skipped turn or a delay to keep the loop honest. This one inverts the math. A 1/1 body buys an extra turn for four mana and a tap, then tucks itself onto the bottom of its owner's library. That tuck is not the payoff, it is part of the activation cost, printed before the colon, so it is non-negotiable: you cannot leave the creature in play, and you cannot substitute bounce to save it, because if the body does not go to the bottom, the cost is not paid and the turn never happens. The card is engineered to bury itself. What throttles the loop is the trip back up through your deck, which means the honest way to reuse it is a tutor that fetches it faster than you would naturally draw it. The city's blessing sits on the same seam: ten permanents is a threshold value and combo decks clear without effort while pure aggro rarely gets there. The result is a turn-machine priced as a build-around rather than a windfall, demanding a deck willing to keep digging the same 1/1 out of the bottom of its own library.