How to beat the Marauders in Doom Eternal
Marauders have two main attacks: close range shotgun explosion and a long range laser beam. As such, if you're too close to the Marauder you'll get a shotgun blast to the face, and if you're too far you'll get hammered with lasers. So you should try to maintain an average distance of Marauders. After you've spent enough time fighting them, you'll get a feel for how far away you need to stay, but it can be difficult to adjust to this new style of play at first.
If you are in the mid-range sweet spot, the marauder eyes with flash green and he will try to swing his ax at you. When the eyes flash green, this is your chance to strike. Shooting the Marauder while his eyes are green will stun him, opening him for more damage. There is also a treble audio cue when he's about to attack too. Listen to the noise so you know when to attack.
When the Marauder swings his ax, you should only use your Super shotgun Or your Ballista, as they are capable of producing significant damage in short bursts. If you hit one with a Super Shotgun blast, they'll be stunned for a few seconds, allowing you to initiate a follow-up attack. When trying to maintain sufficient distance from the Marauders, be sure to use your hyphen to get away from their guns or to dodge their laser beams. Additionally, their shields can block fire, but a fragmentation grenade can still take damage despite their defense. Make sure to throw one in when you have it.
During combat, the Marauders constantly spawn ghostly fire wolves that lie in wait for you. These wolves should be given priority whenever they are in the field. A Super Shotgun blast should bring them down. If you let them linger, they will constantly harass you and distract your attention from the Marauder.
Generally, if you see a Marauder at any point in Doom Eternal, they should take precedence over all other demons in the field. Quickly send elite demons like the Mancubus or Hell Knight so they don't bother you, and use your chainsaw on weaker demons to refuel ammo. Even on normal difficulty, Marauders take a long time to kill in Doom Eternal, but if you follow all of these tips you should be able to kill them easily.