So far, these statistics have come from very small sample sizes, so more information on the odds of the rarities will be better understood after Disney Lorcana is available to the public later this month
They also contain a new cycle of cards that are free to cast if you control your commander, some of which became extremely sought after
For sale is a 100 card custom Magic the Gathering grixis (red/blue/black) curses Commander Deck
Leyline Cycle Duskmourn also has a new cycle of leyline enchantments, which you can place onto the battlefield for free if they're in your opening hand
Amonkhet gave us a very similar cycle of dual lands like Canyon Slough as recently as 2017, and these lands werent as well received as counterparts like Temple Garden or Cinder Glade
After a few turns, if JTMS is not answered, it pretty much takes over the game on his way to an ultimate