It is not necessary to have cards from The First Chapter or Rise of the Floodborn to begin playing Disney Lorcana
What does Black Illusion do

The deck: Desert Plant Tribal Comparative Analysis 36 Lands 30 Ramp : Splendid Reclamation, Wreck and Rebuild, Arcane Signet, Sol Ring, The Mending of Dominaria, Dryad of the Ilysian Grove, Azusa, Lost but Seeking, Aftermath Analyst, Sand Scout, World Shaper, Topiary Stomper, Titania, Natures Force, Desert Warfare, Spelunking, Hour of Promise, Tectonic Split, Vengeful Regrowth, Cataclysmic Prospecting, Worldsouls Rage, Undergrowth Recon, Evendo Brushrazer, Mina and Denn, Wildborn, Map the Frontier, Oracle of Mul Daya, Ancient Greenwarden, Ramunap Excavator, Titania, Protector of Argoth, Exploration Broodship, Elemental Teachings, Mole Man, Moloid Master 10 Target Removal : Grasping Dunes, Desert (ping damage), Wreck and Rebuild, Warstorm Surge, Borborygmos Enraged, Seismic Assault, Aura Fracture, Worldsouls Rage, Chomping Changeling, Omnath, Locus of Rage 2 Board Wipes :Cataclysmic Prospecting, Planetary Annihilation 4 Graveyard Recursion : The Mending of Dominaria, Exploration Broodship, Life from the Loam (Lands), Kirri, Talented Sprout 1 Graveyard Hate : Scavenger Grounds 4 Tutors : Crop Rotation (Land), Elvish Reclaimer (Land), Outcaster Greenblade (land), Colossal Rattlewurm (Desert) 1 Protection : Sylvan Safekeeper 10 Card Draw : Yuma, Proud Protector, Desert of the Fervent (1/2), Desert of the Indomitable (1/2), Desert of the True (1/2), Nahiris Lithoforming, Spelunking (1/2), Sprouting Goblin, Tadeas, Juniper Ascendant, Ark of Hunger, Valakut Exploration, Evendo Brushrazer, Garruks Uprising 3 Finishers/ Surprise /Alternate win conditions : Tadeas, Juniper Ascendant, Rumbleweed, Armageddon As we see from the comparative analysis, the rates per category are good except in ramp category where we see an extreme peak with 30 cards

You can send 1 card from your hand or field to the GY
This card, released with the Cosmic Eclipse set, features both Pokmon cuddling each other
Its entirely possible that Elder Deep-Fiend should occupy this slot, but taking an opponents turn for them is just too romantic to pass up