Repel

Tempo at four mana is a hard sell, and this is the version that pays for itself in card advantage instead of mana efficiency. Sending a creature to the top of its owner's library does two things at once: it removes the threat for a turn, and it strands the opponent's next draw, costing them a fresh card the following turn. That denied draw step is the real wage. Compare it to a bounce spell, which hands the creature back to be recast cleanly: this version forces the opponent to redraw the body they already had, turning a one-shot answer into a soft two-for-one against any deck leaning on a single expensive threat. The cost is that the creature comes back, and comes back to a known top card you can plan around or counter on the way down. The window matters too: at instant speed, it can be held for a declared attacker, a freshly resolved threat, or the end of an opponent's turn to maximize the lost draw. The price of admission is steep enough that it never displaced cheaper interaction in fair blue decks, but the structural idea (deny the card, not just the board presence) is the one worth studying. It is the difference between resetting a creature and taxing the turn that follows.