When you cast a room, you choose which door you are "unlocking." This is the side of the room that is active upon casting
Boros continues to get smashing new tech, with Kirol, Attentive First-Year giving us a free Strionic Resonator each turn
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
Cascade is a powerful effect for sure every time you cast this elf berserker, it brings an extra card with it
Ancestral Blade is one of the first equipment without a mechanic that specifically brought a creature into play with it
