Sylvan Library is such an old card that even the retro frame isnt its oldest frame
You may reveal a Human or artifact card from among them and put it into your hand
Aboshan, Cephalid Emperor Aesi, Tyrant of Gyre Strait Arixmethes, Slumbering Isle Brinelin, the Moon Kraken Caelorna, Coral Tyrant Caetus, Sea Tyrant of Segovia Charix, the Raging Isle Gyruda, Doom of Depths Gyruda, Doom of Depths Kamiz, Obscura Oculus Koma, Cosmos Serpent Koma, Cosmos Serpent Koma, World-Eater Krothuss, Lord of the Deep Llawan, Cephalid Empress Lorthos, the Tidemaker Lorthos, the Tidemaker Marvo, Deep Operative Monstrosity of the Lake Octavia, Living Thesis Queza, Augur of Agonies Shark Shredder, Killer Clone Sin, Spira's Punishment Sin, Unending Cataclysm Slinn Voda, the Rising Deep Taniwha The Terror of Serpent's Pass The Unagi of Kyoshi Island The Watcher in the Water Tromokratis Ultros, Obnoxious Octopus Verazol, the Split Current Wrexial, the Risen Deep Xolatoyac, the Smiling Flood Xyris, the Writhing Storm Yorion, Sky Nomad
So long as The Ur-Dragon is in either one of these zones, your other Dragon spells cost one less generic mana to cast
