Details: 36 Adventures in the Forgotten Realms (AFR) Magic: The Gathering Draft Boosters
Historically, this came about because Wizards R&D would use B for black and L for land, so U became the shorthand for blue and it's been that way ever since
All the other sheets used straight pickups, and we couldn't just do a straight pickup of them, as they weren't in English or could we
This set now sells for tens of thousands on eBay, and even the individual cards have sold for $2-3,000 each
A player granting themselves another turn is close to divine power, especially for such a low mana cost
As far as the deck goes, Arcane Wizardry is a very powerful precon