When you cast a room, you choose which door you are "unlocking." This is the side of the room that is active upon casting
Myrkul, Lord of Bones (Check it out here) was built as the leader of a Midrange and Constellation deck that ran a bunch of dorks with ETB abilities for value (like Liliana's Specter and Archon of Cruelty), sacrificed them for value (High Market and Dockside Chef), netted a return as an enchantment to trigger another ETB for it and constellation dorks (like Underworld Coinsmith and Eidolon of Blossoms) and then added in some ramp, answers, card flow, and called it a deck
It will also allow for more Valki on the battlefield, giving life to Suspend when copies start to get clogged in your hand
Holding cards for coordinated plays later, setting up powerful Songs, knowing when to sacrifice characters to banish an opponent, anticipating the play your opponent is setting up based on their deck composition
While its disappointing to see the best Warhammer faction not get its own Commander deck (stupid Marines soaking up the spotlight), fans will no doubt appreciate more cheeky references
Cascade is a powerful effect for sure every time you cast this elf berserker, it brings an extra card with it
