Gadwick, the Wizened, Blue Sun's Zenith, and Mind Spring are examples of X spells that let your pour extra mana into extra card draw
In a deck with consistent self-mill or fetch lands, this green enchantment puts you ahead a mana every turn
Deepchannel Duelist Deepway Navigator Eclipsed Merrow Galina's Knight Merrow Skyswimmer Namor, Atlantean King Noyan Dar, Roil Shaper Puresight Merrow Sharae of Numbing Depths Sygg's Command Sygg, River Guide Vodalian Wave-Knight
Captain America and Iron Man look impressively powerful, and Black Panther gives players an opportunity to do something that MTG hasnt really seen before
Strength is much less relevant on Bodyguards
Many decks use this reliably, and I can only imagine how many more would do so if it were printed as an uncommon or common