Traverse Eternity

The reward here scales off the wrong-looking number. Most blue card draw pays out per-permanent or per-card-in-hand; this one counts a single stat (the largest mana value among your historic permanents) and turns it directly into cards. That inverts how a deck normally values expensive artifacts and legendaries: instead of wanting many cheap ones, you want a few enormous ones, because one seven-drop Saga or colossal artifact does the whole job by itself. The historic qualifier (artifacts, legendaries, and Sagas) is a deliberately wide net, wide enough that most blue decks with any top-end at all already meet it, but the payoff is gated behind actually deploying that top-end first. The draw is enormous when your board is heavy and embarrassing when it is empty, and unlike a scaling burn or bounce spell there is no floor here worth casting on turn four. Sorcery speed compounds the ask, since you cannot hold it up as a reactive refill; you commit a whole turn to it and want to be sure the count justifies the four mana. It is a refuel button for a deck that has already built a durable, expensive board and now needs to bury an opponent in gas, less a value engine than a reward for having spent early turns assembling something big and permanent.