Gladiator

The gladiator is an armored Hell knight- or baron-like enemy appearing in Doom Eternal which is momentarily shown in the second trailer released on. It carries a large shield and appears to attack with a or  weapon. It resembles the Hell nobles of the original games more strongly than their Doom (2016) or Doom Eternal counterparts. Nothing else is currently known about this enemy.

Lore
In the years following the Golden Age of Argent d'Nur, competing factions of the Argenta turned against each other and a corrupting influence began to distort their sacred traditions.

The Coliseum used to be a place of trial by combat, where prisoners of the Argenta were tested to fight in the front lines of their army, but has since become a place of blood sport. Disregarding Sentinel law, the Priests imprisoned a demon of great power there, and it now acts as equal parts judge and executioner.

The Gladiator's shield contains the tortured soul of its master, and throughout the ages it has resided in the Coliseum it has never been defeated.