You know, it's a shame we have to turn Deregon over to the Science Police-- If I ever doubted the wisdom of the Legion code against killing, it's now! 
Superboy and the Legion of Super-Heroes #229 is an issue of the series Superboy and the Legion of Super-Heroes (Volume 1) with a cover date of July, 1977.
Synopsis for "Hunt for a Hero-Killer"
A team of five Legionnaires goes searching for Deregon, the Dark Circle, and revenge for the death of Chemical King.
Appearing in "Hunt for a Hero-Killer"
Featured Characters:
Supporting Characters:
- Science Police
- Officer Mvar
- Officer Mvar
Antagonists:
- Dark Circle
- Deregon (Final appearance)
- Unnamed Dark Circle member
Other Characters:
- Night Girl (Cameo)
- Chemical King (Flashback only)
Locations:
- Shanghalla
- Dark Circle Citadel
Items:
Vehicles:
Notes
- This issue is reprinted in Legion of Super-Heroes Archives Vol. 13.
Trivia
A plot point is that Wildfire claims that there are 23 active Legionnaires, with the 8th, 13th, 20th, 21st and 23rd to join being (in that order) Superboy, Mon-El, Timber Wolf, Wildfire and Dawnstar.
Other active members at the time include Cosmic Boy, Saturn Girl and Lightning Lad (1st-3rd); Phantom Girl (4th); Colossal Boy and Chameleon Boy (5th-6th); Brainiac 5 (7th); Ultra Boy, Star Boy, Shrinking Violet and Sun Boy (9th-12th); Element Lad, Light Lass, Dream Girl, Princess Projectra, Karate Kid and Shadow Lass (14th-19th); and Tyroc (22nd). Three other Legionnaires had died by this point in time (Ferro Lad, Invisible Kid and now Chemical King), while Duo Damsel, Supergirl, Bouncing Boy and Matter Eater Lad had resigned.
See Also