Insert your card into a penny sleeve first, then carefully slide it into a top loader to prevent any card damage
It looks like most of the coloring is some kind of watercolor with a bit of airbrushing in a couple places, and then the rounded edges are accented with contour lines to better imply the shading and add texture in that kind of way that you see in more formal and older works like medieval manuscripts and bank notes and I think the Winnie the Pooh books did it too
One card at uncommon
Blightbelly Rat Brimaz, Blight of Oreskos Cacophony Scamp Carnival Elephant Meteor Contagion Clasp Contagion Engine Core Prowler Drown in Ichor Everythingamajig Filigree Vector Glistening Sphere Grateful Apparition Grim Affliction Gulping Scraptrap Karn's Bastion Martyr for the Cause Metastatic Evangel Norn's Choirmaster Patrolling Peacemaker Proud Pack-Rhino Recon Craft Theta Scheming Aspirant Spread the Sickness Staff of Compleation Surge Conductor Sword of Truth and Justice Throne of Geth Unbounded Potential Vat Emergence Volt Charge Vraska, Betrayal's Sting Wanderer's Strike Whisper of the Dross Yawgmoth, Thran Physician Yawgmoth, Thran Physician
Post-release, its highly likely the value of these cards will be dramatically different
Out of the main deck, Ritual Monsters are Monster cards that also require a Special Summon called a Ritual Summon