Mohg, the Omen is an optional boss found in the Subterranean Shunning-Grounds. While you may confuse him for Mohg, Lord of Blood, names aren’t the only similarity these two bosses share. If you already fought the Lord of Blood version of this fight, the Omen’s moveset will be familiar to you as it’s almost identical to Phase 1 of Mohg, Lord of Blood.
Mohg, the Omen is immune to status effects and has high fire damage negation.
This boss deals physical/hemorrhage damage, so equipment offering good physical damage negation and robustness can help you mitigate incoming damage.
Mohg’s Shackle can be used two times to restrain the boss for a short while.
The strategy for melee characters here is fairly straightforward. If you freed the Dung Eater in the Subterranean Shunning-Grounds, summon him before entering the boss room. As you enter the boss room, use your sturdiest summon and let them distract the boss as you use charged attacks or the Ash of War: Flame of the Redmanes to repeatedly stagger the boss to use critical attacks to inflict additional damage, and give yourself some breathing room.
Additionally, if you picked up Mohg’s Shackle before reaching this boss, you can use it twice to restrain Mohg and give yourself a small window to use a charged attack or two or the Ash of War: Flame of the Redmanes and hopefully stagger the boss. With these shackles, you have two ways of using them:
If your spectral allies are dying way too quickly, you might consider using the shackles at the start of the fight to have them stay alive a bit longer and deal some more damage to the boss before dying.
You can also use the shackles towards the end of the fight if you need to create an opening to stagger the boss once your friends left you.
If you already used Mohg’s Shackle twice and your summons are gone, you’ll have to finish this fight the old-fashioned way: blocking/dodging and attacking the boss at the end of his attack chains. While most of his melee attacks will be fairly straightforward, there are two attacks that you’ll have to look out for the most: the Bloodflame Talons attack. This attack has two variations: a slower version when the boss puts his trident down first, and a quicker more straightforward one.
In both cases, you’ll want to dodge towards the boss and to your left (the boss’s right) to avoid taking any damage from this attack. Additionally, you should refrain from being overly aggressive, as attacking will make these Bloodflame Talons attacks much harder to dodge. Another thing to look out for will be the Bloodflame Shower attack.
All you can do here is move away from the boss and wait for him to move away from the flames. One thing to keep in mind is that if you use Mohg’s Shackle as the boss is using the Bloodflame Shower attack, you won’t be able to to approach him. Lastly, if you move too far away from the boss while waiting for him to move out of the flames, you run the risk of having the boss use Bloodflame Wave attacks.
If you remain close to the boss, you can avoid these attacks entirely as he will prioritize melee attacks. But if you have to dodge them, you have to keep in mind that there are two variations: a horizontal and a vertical wave. For the horizontal one, you have two choices based on your distance. If you’re really far away from the boss and you see him casting the horizontal Bloodflame Wave, keep running away from the boss until he throws it out and dodge towards the boss once it’s airborne to avoid taking any damage. If you’re at mid-range or close to the boss you can just dodge towards the boss. As for the vertical one, he will only ever use it if you’re at most at mid-range, and all you have to do is either dodge sideways or keep running diagonally away from the boss.
As for the rest of his attacks, they can either be dodged or blocked with a good shield, and shouldn’t pose much of an issue with how little health the boss should have by this point.
The ranged strategy will be nothing special here. As usual, you can rely on your summons and the Dung Eater (if you freed him) to distract the boss while you use ranged attacks/spells from afar. On top of that, if you have access to Mohg’s Shackle, you can use it twice during this fight to immobilize the boss for a few seconds. If you are all alone and your summons are dead however, you will have to a bit more careful as you use ranged attacks. While the boss will be slowly walking towards you and won’t seem to be in a rush, you should start using quick attacks/spells as he will be able to quickly close the gap once you start attacking.
Another thing to look out for will be the Bloodflame Wave, which can be dodged by running away from the boss until he throws it your way, and dodging towards the boss once it’s airborne.
Lastly, with this boss being immune to status effects and resistant to fire damage, prioritize attacks that deal upfront non-fire damage.