27 Apr 2018
Demonlord Belzenlok's ability causes it to deal an amount of damage to you all at once; it doesn't deal 1 damage multiple times.
27 Apr 2018
Land cards exiled this way remain exiled.
27 Apr 2018
If the mana cost of the nonland card includes {X}, X is considered to be 0.
27 Apr 2018
The mana value of a split card, such as a card with aftermath from the Amonkhet block, is equal to the combined mana cost of its two halves.
27 Apr 2018
Once the triggered ability resolves, the ability will continue until you either exile a nonland card with mana value 3 or less or fail to exile any nonland cards while performing the process. You can't choose to stop receiving the blessings of Demonlord Belzenlok any sooner.
27 Apr 2018
If the nonland card doesn't have a mana cost, its mana value is 0.