The combination of mana ramp and card drawing ensures card advantage and mana smoothing for any deck
Ayara, Furnace Queen Baeloth Barrityl, Entertainer Bloodbraid Challenger Bloodbraid Elf Brazen Upstart Delina, Wild Mage Fleetfoot Dancer General Marhault Elsdragon Godtracker of Jund Grand Warlord Radha Hallar, the Firefletcher Jinnie Fay, Jetmir's Second Kalain, Reclusive Painter Knotvine Mystic Marhault Elsdragon Mayael the Anima Meria's Outrider Meria, Scholar of Antiquity Mina and Denn, Wildborn Naya Hushblade Naya Sojourners Neera, Wild Mage Obuun, Mul Daya Ancestor Radha, Coalition Warlord Radha, Heart of Keld Radha, Heir to Keld Rakish Revelers Rashmi and Ragavan Rocco, Cabaretti Caterer Rocco, Street Chef Shalai and Hallar Tana, the Bloodsower The Neutrinos Yavimaya Barbarian
How I wish they could further add more features on this app: like an option to play a certain structure deck versus another structure deck with an AI (or another player for online capabilities) and a DECK BUILDER, allowing you to mix and match cards from other structure decks or booster packs
Some of them, like Chupacabra Echo, give -X/-X to other creatures, while others, like Ravenous Chupacabra and Shriekmaw, straight kill them