Bring on the Bad Guys: Sinestro

Real name: Thaal Sinestro

First appearance: Green Lantern II#7 1/2 (July/Aug. 1961)

Abilities: Yellow Power Ring

Worst act: Murder, attempted conquest of galaxy

Quote: "Silence! Or all of you will get the same treatment! I am Green Lantern--no one can tell me what to do!"

Created by: John Broome (script), Gil Kane (pencils), Joe Giella (inks)

Tempted to have this guy on the 22nd, but I found a better candidate. Hal (in this continuity) first encounters Sinestro when a town he was visiting vanishes. The Guardian of the Galaxy kidnap him, again, and explain Sinestro's deal. 

Seems he used to be a Green Lantern, and a darn good one too until he went full fascist and took over his home world. The Guardians, stepping up for once, stripped him of his powers and banished him to the world of Qward. You know, that place filled with guys who make crazy weapons and who all hate you?

Seems the Weaponers aren't bothered by Thaal's faux pas so they hook him up with a Yellow Power Ring, which is exactly the same as the Green Lantern's Power Ring only its yellow, i.e. the only thing that the Green Lantern's are vulnerable to; good plan guys. 

Hal manages to outwit both the Weaponers and Sinestro, which doesn't speak of either group really, especially since Hal uses the old 'move the clock forward' bit. 

As a concept, I rather like the Training Day approach. Good cop gone bad is an easy story to sell and it hit harder if Hal and Thaal are friends first then enemies. Easy to see why he's hung around to the present day though.