Who's Who: The Blight

The Blight
by Siskoid

Super-Power(s): Corruption
Planet of Origin: Unknown

Relationship to Legion: Enemies

Who's Who: Elements of Disaster

Elements of Disaster
by Siskoid

Members: Phy'r, Rrok (or Rrox), A'rie, and Ebb
Real Names: Dirk Morgna, Brika, Flutter, and none

Super-Power(s): Control over each of their elements
Planets of Origin: Earth, Dyrad, Swizzar, and unknown

Relationship to Legion: Enemies

Who's Who: Pernisius

Pernisius
by Siskoid

Real Name: Lord Pernisius

Super-Power(s): Harnessing the energies of Eternium
Planet of Origin: Rimbor (birth world unknown)

Relationship to Legion: Villain

Who's Who: Zera Vultan

Zera Vultan
by Russell & Siskoid

Real Name: Zera Vultan

Super-Power(s): None
Planet of Origin: Earth

Relationship to Legion: One-time enemy

Who's Who: Zaryan the Conqueror

Zaryan the Conqueror
by Russell & Siskoid

Real Name: Nalhrog Zaryan

Super-Power(s): Ruthlessness
Planet of Origin: Brok

Relationship to Legion: Enemy

Who's Who: Worldsmith

Worldsmith
by Russell & Siskoid

Real Name: Unknown

Super-Power(s): Unspecified mental powers, which at least seemed to include the ability to change a planet's surface to stone, earth or water
Planet of Origin: Planet

Relationship to Legion: Enemy

Who's Who: Weight Wizard

Weight Wizard
by Russell & Siskoid

Real Name: Nik Obershaw

Super-Power(s): Ability to increase and decrease his own mass
Planet of Origin: Earth

Relationship to Legion: Antagonist

Who's Who: Vibrex

Vibrex
by Russell & Siskoid

Real Name: Dist Vetkoh

Super-Power(s): Vibration projection
Planet of Origin: Jupiter

Relationship to Legion: Villain

Who's Who: The Unkillables

The Unkillables
by Russell & Siskoid

Real Name: Various; see below

Super-Power(s): Advanced strength
Planet of Origin: Earth

Relationship to Legion: Adversaries

Who's Who: Uli Algor

Uli Algor
by Russell & Siskoid

Real Name: Uli Algor

Super-Power(s): None; advanced technological weapons
Planet of Origin: Skor

Relationship to Legion: Adversary

Who's Who: Tusker

Tusker
by Russell & Siskoid

Real Name: Horace Lafeaugh

Super-Power(s): Extending tusks
Planet of Origin: Earth

Relationship to Legion: Would-be Ally, now Adversary

Who's Who: Tseln

Tseln
by Russell & Siskoid

Real Name: Tseln

Super-Power(s): None
Planet of Origin: Thaun

Relationship to Legion: Villain

Who's Who: Taurus Gang

Taurus Gang
by Russell & Siskoid

Members: Group consisting of Black Mace, Mystelor, Quanto, Rogarth, and Shagrek
Super-Power(s): Power (see individual listings below)

Planets of Origin: Various 

Relationship to Legion: Adversaries

Who's Who: Starlight and Starbright

Starlight and Starbright
by Russell & Siskoid

Real Name: Unknown

Super-Power(s): Both sisters can fly and are super-strong; Starlight shoots black light beams of destruction; Starbright drains the energy of her antagonist via her "star shield." 
Planet of Origin: Unknown; found by Starfinger II in the desert of Mars

Relationship to Legion: Adversaries

Who's Who: Starburst Bandits

Starburst Bandits
by Russell & Siskoid

Members: No individual names ever given

Super-Power(s): Bursts of stellar energy from their palms
Planet of Origin: Unknown

Relationship to Legion: Adversaries

Who's Who: Sklarian Raiders

Sklarian Raiders
by Russell & Siskoid

Planet of Origin: Sklar

Relationship to Legion: Adversaries

Who's Who: Size Lad

Size Lad
by Russell & Siskoid

Real Name: Aarl

Super-Power(s): Ability to make any object larger or smaller; the power is temporary
Planet of Origin: Murra

Relationship to Legion: Villain; temporary Legionnaire

Who's Who: Servants of Darkness

Servants of Darkness
by Russell & Siskoid

Members: Guardian, Kalibak, Lydea Mallor, Orion, Superman (clones)

Relationship to Legion: Villains

Who's Who: Seerons

Seerons
by Russell & Siskoid

Super-Power(s): Telepathy, telekinesis, mind control, time control
Planet of Origin: Seeris

Relationship to Legion: People helped by the team

Who's Who: Sden

Sden
by Russell & Siskoid

Real Name: Sden

Super-Power(s): Magic
Planet of Origin: Trevenon

Relationship to Legion: Adversary