These decks are shared by the community and already available to pick in any game lobby, so there's no need to clone one just to play it. Clone a deck only if you want to customize it or use it as a starting point for building your own.
Grist, the Hunger Tide
Nekusar, the Mindrazer
Karn, Gilded Guardian
Marneus Calgar
Szarel, Genesis Shepherd
Vislor Turlough
The Second Doctor
Ms. Bumbleflower
Gisa and Geralf
Gishath, Sun's Avatar
Atraxa, Praetors' Voice
Shalai and Hallar
Ravos, Soultender
Kodama of the East Tree
Ultima, Origin of Oblivion
Aerid Konstrari
Morophon, the Boundless
Quandrix, the Proof
Naban, Dean of Iteration
Gollum, Riddle Master
Go-Shintai of Life's Origin
Cosmic Spider-Man
Captain America, Team Leader
Avatar Aang // Aang, Master of Elements