These champions are associated or with Noxus:

Cassiopeia, the Serpent's Embrace
Dr. Mundo, the Madman of Zaun
Katarina, the Sinister Blade
LeBlanc, the Deceiver
Morgana, the Fallen Angel
Singed, the Mad Chemist
Sion, the Undead Champion
Swain, the Master Tactician
Talon, the Blade's Shadwo
Urgot, the Headsman's Pride
Vladimir, the Crimson Reaper
Warwick the Blood Hunter

Alistar, the Minotaur
Annie, the Dark Child
Gragas, the RAbble Rouser
Mordekaiser, the Master of Metal
Riven, the Exile
Sivir, the Battle Mistress
Twisted Fate, the Card Master
Xin Zhao, the Seneschal of Demacia