If you're just getting started, it's better to focus on building a solid deck with starter decks and then gradually add cards from booster packs as you become more familiar with the game
I'll be honest and say, I voted for Blaster and Monster Reborn

Abandon Attachments Advanced Stitchwing Alberix, the Trade Planet (playtest) Alexi, Zephyr Mage All-Seeing Arbiter Ancestral Memories Anurid Brushhopper Arm-Mounted Anchor Artificer's Epiphany Artistic Refusal Atemsis, All-Seeing Battle of Frost and Fire Battlewing Mystic Bazaar Trademage Bazaar of Baghdad Big Score Bitter Reunion Brilliant Spectrum Byway Barterer Cait, Cage Brawler Calamitous Tide Calim, Djinn Emperor Careful Study Case of the Crimson Pulse Catalog Cathartic Pyre Cathartic Reunion Cephalid Sage Ceta Sanctuary Champion of Wits Chandra, Flamecaller Chart a Course Cipherbound Spirit Compulsive Research Dangerous Wager Daretti, Scrap Savant Demand Answers Desperate Ravings Does Machines Dreamscape Artist Electric Revelation Emmessi Tome Experimental Pilot Fable of the Mirror-Breaker Fae of Wishes Faithful Mending Faithless Looting Falkenrath Pit Fighter Farm // Market Fast // Furious Fearless Swashbuckler Flow of Knowledge Forbid Frantic Search Gallia of the Endless Dance Galvanic Giant Ghastly Discovery Grab the Prize Greasewrench Goblin Gurzigost Harnfel, Horn of Bounty Hearth Elemental Hieroglyphic Illumination Highway Robbery Honor the God-Pharaoh Hypothesizzle Ill-Timed Explosion

In this way, Lillie's weaker Pokemon don't represent as much of a liability to the rest of your team
Can Waterbending Reduce Colored Costs
resolve one cascade trigger and the spell you cast from it before resolving the next cascade trigger