For One Mana highlights one mana cards you could be playing but arent, in an attempt to make you diversify your one mana plays over grabbing the easy auto-includes you keep seeing in every game
for instance, a matchup I saw a few times was Thalia vs Scythe Tiger While Thalia could attack for 2 damage, and Scythe Tiger would die if it blocked her due to first strike, Thalia should not attack, because Scythe Tiger can then attack back facing no blockers
Compared to other sets, Aether Revolt and Hour of Devastation booster boxes appear underpriced
Its a tutor that casts the card right away, and if you pay five colors of mana, you can get something like Niv-Mizzet Reborn, which draws you a bunch of cards, or more redundancy for other combos like Scapeshift
La Campina Romana by Claude Lorrain (1639)
The mechanic showed up again in the Time Spiral block in 2006