As someone whos lost so many games to board wipes, its amazing to have Elf commanders who dont immediately fold to a Wrath of God since Miara can at least refill your hand with more gas, not to mention giving you access to reanimation spells to get your army right back
Players can't take any other actions until you're done casting the spell.
Now add to the mix Lands-matter pieces like Lotus Cobra, Nissa, Resurgent Animist, Amulet of Vigor, or Tiller Engine, and Lumra starts converting every returning Land into extra untapped mana, extra triggers, and a very real path to winning the game
Its an artifact token generator, a card draw engine, a cast-from-exile enabler, and just a fine reward for hitting opponents (AKA breaking faces)
Some of these cards are strictly better than others, but are harder to trigger