Iron Knuckles wears a red and gold suit made of iron. It includes a helmey with two glowing blue eyes. The suit allows him the ability of flight.
Ugandan Knuckles Infinity War
The Avengers Knuckles attempted to defeat Thanos Knuckles, but they were unsuccessful. At some point, Thanos Knuckles has Iron Knuckles and Spider-Knuckles alone, and he used the Infinity Gauntlet to kill Spider-Knuckles, leaving Iron Knuckles emotionally distraught.
Thanos Knuckles later used this scene to demonstrate to other crowds his power.
It is unknown if Thanos Knuckles let Iron Knuckles live.