Force of WillForce of Will (230,961 Inclusions, 11% of 2,065,626 Decks) Force of WillForce of Will is one of the first boogey-man cards you learn about when you start playing Magic
Oh, and hes a 6/6 flyer
Pressuring opposing life totals and resources via the hand attacks your opponents on multiple fronts, making it hard to counter, and its near immortality gives you all the tools necessary to win a long, grindy game
This also applies to mirrors: a bonus attack is just better than not dying most of the time, especially when end games are largely impossible to kill Hazoret the Fervents
In the earliest days of the game, Trainer cards had no restrictions on their use, so with the maximum 4 copies allowed in the deck, a player could draw 8 extra cards in one turn if they were all in the hand during the same turn