If she ever dies, you get to put X +1/+1 counters onto each legendary creature you control, where X is the number of +1/+1 counters on Aerith
FromTheShire: You probably don't have a ton of non-mana rock artifacts out early for the improvise outside of very specific decks so it's not exactly a new staple
Individual cards from the set, meanwhile, run the gamut of values from a few cents to several thousand dollars for rare MTG cards such as legendary land The Tabernacle at Pendrell Vale, according to MTGGoldfish

Approach of the Second Sun As Luck Would Have It Azor's Elocutors Barren Glory Battle of Wits Biovisionary Call the Spirit Dragons Central Elevator // Promising Stairs Central Elevator // Promising Stairs Chance Encounter Coalition Victory Darksteel Reactor Doctor Doom, Unrivaled Duelists' Convocation International (playtest) Epic Struggle Felidar Sovereign Form of the Approach of the Second Sun Gallifrey Stands Halo Fountain Happily Ever After Hedron Alignment Helix Pinnacle Hellkite Tyrant Jace, Wielder of Mysteries Laboratory Maniac Laboratory Maniac Liliana's Contract Luck Bobblehead Mayael's Aria Maze's End Mechanized Production Mortal Combat Near-Death Experience Now I Know My ABC's Ramses, Assassin Lord Revel in Riches Shinryu, Transcendent Rival Simic Ascendancy Test of Endurance Thassa's Oracle The Cheese Stands Alone Triskaidekaphile Twenty-Toed Toad Wowzer, the Aspirational (playtest)

Some of the single-target discard spells arent great in Commander, but I made sure to highlight the cards that are good in Magics most popular format
3 turns is quite a lot of game time in Modern to swing something back in your favor, especially at 1 CMC