When it ETBs or when a foe draws a card that's not the first card in their draw step, this flashing things trigger
They do come with a cost to sacrifice, but are still worthy
Best to just see where things go next, cross your fingers, and then throw an enormous party if you manage to pull such a rare card when ripping packs
Once a creature has been hosted at a Realm, that creature remains hosted until it or the Realm leave the battlefield
Equipment Matters / Metalcraft This one is a little less likely, but if the set opts to use artifacts for many of the relics and weapons of the Third Age, then metalcraft or other equipment payoffs are mechanics that could work
All permanents with daybound will be on that face when it is day, and will all transform to their nightbound side when it turns to night be having a player not cast any spells on their turn