Each type has its strengths, and these strengths can be combined with other Ink types, though each deck can only have two types
I dont quite know
franchise is globally popular
Effects like Strionic Resonator or extra turn spells to get repeated instances of this ability are necessary

Aerie Worshippers Aether Channeler Ageless Sentinels Airborne Aid Akim, the Soaring Wind Alrund's Epiphany Animal Sanctuary Attempted Murder Aven Brigadier Aven Initiate Aven Warhawk Aven Wind Guide Azorius Keyrune Bartz and Boko Battle Screech Beck // Call Beck // Call Call the Mountain Chocobo Case of the Filched Falcon Celestial Gatekeeper Chicken Egg Chicken la King Choco-Comet Chocobo Camp Chocobo Racetrack Cloudreach Cavalry Crow Storm Dazzling Denial Dovescape Eccentric Apprentice Emeria Angel Eyes in the Skies Fable of Wolf and Owl Falcon and Redwing Falcon, Winged Wonder Falconer Adept Flurry of Wings Fowl Play Glint Hawk Idol Goblin Bird-Grabber Gwaihir, Greatest of the Eagles Gysahl Greens Hermes, Overseer of Elpis Jeskai Monument Jeweled Bird Jolrael, Voice of Zhalfir Jtun Owl Keeper Kangee, Aerie Keeper Kastral, the Windcrested Knight of Doves Knightfisher Liberated Livestock Lilypad Village Love Song of Night and Day Lupinflower Village Migratory Route Mockingbird Mu Yanling, Sky Dancer Murmuration Murmuring Mystic Oketra's Attendant Ominous Roost Ordered Migration Ornitharch Perch Protection Pride of the Clouds Radagast, Wizard of Wilds Raven Guild Initiate Raven Wings Ravenform Rendmaw, Creaking Nest Restless Anchorage

If there aren't eight or more cards in your graveyard at that time, the ability won't resolve and none of its effects will happen