You can see an overview here: 90% (4th card), 60% (5th card) 5% (4th card), 20% (5th card) 1.666% (4th card), 6.664% (5th card) 2.572% (4th card), 10.288% (5th card) 0.5% (4th card), 2% (5th card) 0.222% (4th card), 0.888% (5th card) 0.04% (4th card), 0.16% (5th card) So, if you open 1,000 boosters, there should be one to two cards of the crown rarity
Upon entering, players will choose one of three mystery boxes, each containing a farming tool
The character-heavy set is once more finished with a flourish and a Cid, this time in full flight as an adventurous gnome
The Tabernacle at Pendrell Vale is also pretty broken as a land that can wrath away your opponent's board or at least heavily tax your opponent's mana each turn