Elseworlds: Superboy's Last Legion Adventure
Takes place immediately after the back-to-back disasters of Earth War and Omega Event.
Despite Wildfire's never-surrender pep talk, Superboy is finding it difficult to sustain his ideals. A confrontation with the imprisoned Brainiac Five, now fully embracing his villainous legacy, disillusions Superboy further.
During an attempt to quell a rise in piracy on Rimbor, Ultra Boy and Mon-El are killed by Titania and Silver Slasher, assassins employed by the mysterious Shadow Lords.
On Earth, the Legion Espionage Squad fails to capture three more of the Shadow Lords' assassins -- Neutrax, Mist Master, and Lazon -- but does unexpectedly save the lives of Tharok and Validus, who had run afoul of the Shadow Lords.
Shadow Lass is hungry for revenge and outraged by suspicions that she is somehow connected to the Shadow Lords. She questions her cousin Grev, a reformed delinquent now attending the Legion Academy. This leads to a confrontation on Talok between herself and the final assassins, Blok, who surrenders to her.
Blok reveals the location of the Shadow Lords base to the Legionnaires. It is an uncharted exoplanet in a sector known to be heavy on piracy. Against Superboy's wishes, more than half of the team decides to use a thief to catch other thieves. Namely, Tharok and Validus become temporary allies of the Legion.
A large team of Legionnaires raids the exoplanet. The Shadow Lords are revealed to be Cosmic King, Lightning Lord, and Saturn Queen. During the clash, Dawnstar is nearly killed when Neutrax de-powers her in mid-flight, leading an enraged, irrational Wildfire to kill Neutrax; Saturn Girl leaves Saturn Queen comatose after the latter fries Tharok's brain; Cosmic King burns Cosmic Boy by turning metallic debris into acid; Lightning Lad and Lightning Lord kill each other. And Shadow Lass traumatizes Silver Slasher by surrounding her in darkness.
Superboy, seeing no relief from the grimness that has overtaken this once-utopian future, resigns from the Legion, returns to the present and quits super-heroics, becoming a social activist.
NOTE: Yes, this was a dark one. I suppose I had to get it out of my system. Hopefully, there are brighter ideas to come.