Welcome to the Leyline Cube!

Drafts work as normal, with one major twist:
After the draft has finished, each player may choose one of 10 two color cards that do not appear in the draft otherwise. These cards should determine what that player builds, as these cards will act like emblems for the player. Each player starts each game with their chosen "Leyline" in the command zone. These cards may not be cast from the command zone, but rather give the player a passive (or active) ability. Any static, activated, or triggered abilities of these cards function the same as if they were on the battlefield, but the cards themselves may not be targeted, destroyed, sacrificed, or otherwise interacted with. They do not count as being on the battlefield. "Leylines" with ETB effects have unique ruling: if your leyline has an ETB ability, you may choose to use it once at any point in the game. If your leyline is an aura, a similar ruling takes effect: once per game, at any point in the game, you may choose a creature for the aura to take effect on. The creature does not count as being enchanted, but gains all of the benefits of the aura itself. Leylines may transform in the command zone, and may tap as well. They untap in your untap step.

It's more simple than I made it sound; basically, when building your deck you get to choose a special enchantment to build around, and that enchantment works similarly to an emblem or a conspiracy for you. Each card works more with the spirit of the card than the actual rules- like choosing demonspine whip gives all of your creatures ": This creature gets +X/+0"