Marauder

"You were never one of us. You were nothing but a usurper, a false idol. My eyes have been opened. Let me help you to see, Slayer."

- A Marauder addressing the Doom Slayer.

The Marauders are a group of resurrected Night Sentinels who sided with the Khan Maykr and the Hell Priests against the realm of Argent D'Nur. As former members of the Doom Slayer's personal band of warriors, they have access to a wide range of techniques that make them one of the most challenging and deadly foes the player will face over the course of the campaign.

Codex
''As civil war consumed Argent D'Nur, the Night Sentinels Guard was quartered by their faith. Torn between serving the Khan Maykr or revolting against that which they swore to protect. Those most disillusioned forswore their oath to the Sentinel royalty, abandoning their pact of allegiance made to the throne. These hardened warriors joined the separatist group led by the exalted Priest class, allying themselves with the Maykrs and their devout acolytes in an attempted coup against the Sentinel royal house. Those Sentinel warriors who fell in battle, having sided with the Maykrs, were ultimately denied finality in death. Resurrected by the Divinity Machine of Maykr design, these fallen Sentinels were returned from the dead, transformed by Hell's power, and recreated with a singular purpose: to hunt the Slayer, now reborn as Knights in Hell's army.''

Appearance
The Marauder resembles a humanoid wearing Sentinel armor. It notably wields a large battleaxe, using similar energy to the Slayer's Crucible. It also wields its own double-barreled shotgun. Likely due to its resurrected state, its skin is a pale white, and it features a large set of horns on its head. The Marauder's eyes also glow a deep red, not dissimilar to the Hellified Soldiers.

Combat Analysis
To effectively duel with a Marauder, the player must understand the spacing gimmick that revolves around it. At longer distances, the Marauder will hurl a beam of energy at the Slayer. At close range, it will fire upon them with its Double-barreled Shotgun. And at medium distances, the Marauder will lunge at the player with its axe. The Marauder will also summon a wolf to chase the Slayer at random intervals, though it seems more likely to do so after it blocks the Slayer's attacks.

The player must keep combat with the Marauder at medium distances, for the Marauder is only vulnerable to attack when it is in mid-lunge. The player can tell a Marauder is about to lunge at the Slayer when its eyes flash green and a sound cue plays. During the window in which the Marauder is lunging at the Slayer, hit it with a powerful weapon such as the Super Shotgun or Ballista to falter it for roughly a second. This gives the player just enough time to follow up with a second shot before the Marauder recovers. Repeat this cycle several times and the Marauder will fall.

The Marauder is incredibly durable and notably is unaffected by the Ice Bomb and Chainsaw. It will also use its shield to block the BFG's  tendrils, negating damage from it, though as it is occupied with the projectile, a window of opportunity to attack it from behind is open to the player for as long as the projectile is in range. It can also block the Crucible's swing, though it is not impossible to kill it this way, as shown in this video.

The Marauder is one of the most dangerous and challenging enemies in Doom Eternal, requiring the player's attention at all times. However, keeping your surroundings in your peripheral vision is just as important; focusing too much on the Marauder can allow for an opening for another demon to kill the Slayer.

Battlemode
The Marauder also serves as one of the several playable demons in Doom Eternal's Battlemode. With a base health of 2000, it serves as a flexible, if fragile, demon that has access to several different attacks. Similar to its depiction in the campaign, the Marauder wields both its Argent Axe and Super Shotgun and is capable of summoning its trusty Wolf to harass the Slayer. However, it no longer has access to its impenetrable shield to block the Slayer's attacks.

Trivia

 * The Marauder bears some resemblance to Death Knight from Quake.
 * If one were to peer at his chest in the ARC Laboratory cutscene, a series of dark purplish veins seem to emanate from where the red light on his chest piece rests. It may imply that some parts of the armor - or at least, that particular piece - is fused to his very body.
 * During combat, if the player listens carefully, the Marauder's grunts are actually Ranger's grunts from Quake III: Arena.
 * The Marauder's voice actor is Edward Bosco, also voices the game's main antagonist Icon of Sin. who also voiced Kan-Ra and Gargos in Killer Instinct (2013).
 * The Marauder is one of the first demons in the Doom series to speak English.