Any physical renderings (Splash arts/concept art)?

While I suspect all art for the game is finished digitally (splash arts mostly) is there any record of artists that have done sketches or physical copies before scanning into digital format? I am a beginner collector of art from card games (Magic the Gathering, World of Warcraft, and Kaijudo, etc..) and was hoping that something might exist for league. Would love to have an original from this game that I have enjoyed so very much.

While I would prefer something of Morg/Thresh /Xerath Id be open to anything really.

Thanks for your time! ~~BNjoeC