The Plutonian's essence is what inspired the original design/creation of Superman. Without him, Shuster/Siegel would've never come up with the idea:
http://i.imgur.com/p0ej0fp.jpg
http://i.imgur.com/2Y9KVyP.jpg
http://i.imgur.com/cARZfhH.jpg
http://i.imgur.com/25vgQYB.jpg
http://i.imgur.com/3Q5R860.jpg
http://i.imgur.com/JmQ42Hj.jpg
http://i.imgur.com/L90ZYQ9.jpg
So clearly the Plutonian is the greatest Superman of them all. vin