Dyogene

Origin

 Born of the essence of Oa to replace Mogo, Dyogene was called up by the remaining commands of the Guardians of the Universe (by now long dead) in the 31st Century as Professor Harmonia Li and her partners in the Time Institute (now located on Titan due to the events of the Justice League Earth and the Legion of Three Worlds) decide to look back to the beginning of the universe, ignoring the old legends and warnings of doing so (the damage of the act (so far) destroys Titans).  
 With the forces of the Green Lantern Corps diminished down to one (Sodam Yat) Dyogene picks up one of the fallen power rings and sets out to Earth to rebuild the Corps. He first offers the ring to Kirt Niedrigh a.k.a Earth-Man (former leader of Justice League Earth, former member of the Legion of Super-Villains). Earth-man accepts the ring, but then gives it up after completing his first Green Lantern mission, throwing it into a swamp on a primitive planet and is later retrieved by Dyogene.  
After his failure in his choice of Green Lantern, Dyogene returns to Oa to return to the soil and allow for more time to pass before choosing a new Lantern. Sodam Yat prevents Dyogene to return to his sleep and hurles him off into space to continue his mission. He then offers the ring to Professor Li on Naltor (now the home of the Time Institute after Titan’s destruction) only to have her throw it away in disgust as if it was a plague, and insulting the guardians. Dyogene then travels to the headquarters of the Legion of Super-Heroes to find the new lantern (bumping into Earth-Man again). Cosmic Boy decides to help Dyogene and calls all of the Legionnaires in the clubhouse to the conference room so that Dyogene can chose who is worthy or not. One rejects the ring, others are found unworthy, and one incompatible. Dyogene then offers the ring to the only Legionnaire in the room who’s worthy (Mon-El) who accepts and then later flies off with Dyogene. 
 

Creation

 Dyogene made his debut in the first issue of Legion of Super-Heroes (Vol.6), written and created by Paul Levitz and Yildiray Cinar.