Its adventure can keep your creatures safe for a turn at a fair price, and this cards attack trigger is also great in a deck type that usually goes wide
If they are featured as MTG cards, there are plenty of cards that match the Chaos Emeralds abilities

Adder-Staff Boggart Afterburner Expert Akki Avalanchers Akki Battle Squad Akki Blizzard-Herder Akki Coalflinger Akki Drillmaster Akki Ember-Keeper Akki Lavarunner Akki Raider Akki Rockspeaker Akki Ronin Akki Scrapchomper Akki Underling Akki Underminer Ankle Shanker Ardoz, Cobbler of War Arms Dealer Auntie Ool, Cursewretch Auntie's Snitch Battle Cry Goblin Battle Squadron Battle-Rattle Shaman Battle-Scarred Goblin Bazaar Trader Beetleback Chief Ben-Ben, Akki Hermit Bile-Vial Boggart Blackcleave Goblin Blisterstick Shaman Bloodcrazed Goblin Bloodmark Mentor Bloodshot Trainee Bloodstone Goblin Boartusk Liege Bog Hoodlums Boggart Arsonists Boggart Birth Rite Boggart Brute Boggart Cursecrafter Boggart Forager Boggart Harbinger Boggart Loggers Boggart Mischief Boggart Mob Boggart Prankster Boggart Ram-Gang Boggart Shenanigans Boggart Sprite-Chaser Boggart Trawler Boltbender Boneclub Berserker Boom Scholar Boomstacker Boros Recruit Brash Taunter Breeches, Brazen Plunderer Breeches, Eager Pillager Breeches, the Blastmaker Broadside Bombardiers Burnout Bashtronaut Cacophony Scamp Cam and Farrik, Havoc Duo Caterwauling Boggart Champion of the Weird Chaos Spewer Chasm Guide Cheering Fanatic Chimney Rabble Clamor Shaman Conduit Goblin Conspicuous Snoop

You cant do this if youre putting the cards in a PWE, but if youre mailing that many cards, it should probably be in a bubble mailer anyways
That might sound narrow until you realize how many important creatures fall into that range