Elden Ring features a huge array of deadly bosses for players to track down and face in combat, and some of the most dangerous can be found hidden in optional areas. Mohg, The Omen, is one such boss, found hidden in the depths of the Subterranean Shunning Ground and guarding the path to the Three Fingers.
One of Elden Ring's strongest bosses, found in another late-game area, is Mohg, the Lord of Blood. Mohg the Omen is an illusory projection of the Lord of Blood, much as Margit is an illusory projection of Morgott. Despite this, 
Mohg, the Omen is an incredibly deadly character who actually boasts several advantages over the true Mohg, and can be quite the hazard to unprepared players. Here's a breakdown of how to fight him.
Boss Overview - Attacks
Mohg, The Omen shares his entire moveset with the first phase of Mohg, Lord of Blood. Mohg attacks using both his trident and an array of blood/bloodflame attacks. This means the majority of his damage is fire and inflicts the hemorrhage status effect, which can take huge chunks out of the player's health if not managed properly. Staunching Boluses are useful for managing Hemorrhage if it builds up, but the best way to avoid it is by using armor with high bleed resistance and avoiding his attacks.
Mohg uses Bloodflame talons to swing from his right to his left, leaving crimson claw marks that explode into blood lames. It is best to roll right before the explosion to avoid the damage from this attack. He can also reach upward through a portal and hurl in a horizontal arc. This blood does damage on contact and lingers in pools on the floor for a while, causing additional damage and bleed build-up if the player stands in it. Sometimes Mohg will reach into the portal and instead create a line of blood rain ahead of him, which functions similarly to the horizontal arc but requires different dodging methods.
Players can dodge the Horizontal arc by rolling backward or forward through the arc. Forward tends to work better and also puts melee fighters in range of Mohg most of the time, but backward might be a safer call for squishier builds relying on spells or other sources of ranged damage. Players will instead need to roll to one side in order to avoid the line of rain. Mohg tends towards the arc when players are close to him, and uses the line more often when players are further away, though the presence of summoned help can make him slightly harder to predict.
When Mohg swings his spear, he does so in combos of 3–4 hits that can be dodged fairly easily by rolling towards him and in the direction the swing is coming from, and the spear slams he ends the combo with leaves him open to counterattack for a while. He can also hold the spear forward and charge toward the player. While this does lots of damage, it also leaves a huge opening for players to attack if it is dodged successfully.
As mentioned before, this is all fairly identical to the first phase of Mohg, Lord of Blood's boss fight, so the guide linked at the beginning of this article provides some very useful advice for this fight. This next section explains the main differences between the two fights.
Boss Overview - Resistances and Stance Breaking
Unlike his later appearance as the Lord of Blood, this version of Mohg is entirely immune to all status effects, including bleed. This means players will need to rely on raw damage output to deplete his substantial health bar. He can also be stance broken fairly easily with weapons that deal good poise damage, leaving him vulnerable to critical attacks and/or providing an opportunity for players to heal and cast slower spells. He retains his 80% resistance to fire damage, so players should try to avoid using fire against him.
He is the least resistant to physical damage, so making use of physical damage via weapons or spells like Rock Sling and Meteor is the most effective way of damaging Mohg during this fight, though his 40% resistance to all elemental damage types apart from fire can easily be overcome by a dedicated build focusing on those damage types. Fire-focused builds who wish to stick to their guns should consider using fire magic with high poise damage, like Frenzied Flame or Unendurable Frenzy, or take advantage of the additional percentile damage dealt by Black Flame incantations.
As with the Lord of Blood, players should aim to take advantage of the openings left by his spear combos and charge to hit him. Players can also make use of Mohg's Shackle, found in the same Subterranean Shunning Grounds that the boss inhabits, to lock him to the ground and leave him open to attacks for a time.
Elden Ring is available for PS4, PS5, PC, Xbox One, Xbox Series X/S, and Nintendo Switch.
