Stone Cold Badge
From City of Heroes: Rebirth - Wiki
Description
You took out a filthy traitor to the Port Oakes Vendetti Family.
How to Get
To earn the Stone Cold Badge, you must complete the mission to deal with Niles Worthington assigned by Angelo Vendetti.
As a Flashback mission, you must complete "Hurt the Traitorous Vendetti" in the Soldier (Level 1-15) section.
Gladiator Badge Unlocked
When you earn this badge, you will unlock the Mook Capo Gladiator badge.