- If he claws the area in front of him, a small explosion will appear after a delay. Wait a beat, then dodge roll backwards to avoid the damage. If he reaches behind and charges up the spell, the explosion will be bigger but focused directly in front of him, making it easy to sidestep and strike him a few times.
- If you are far out of melee range, he will summon a magic rune above him, reach into it, and then quickly fling a wave of blood at you. You can avoid this by simply rolling toward the blood as it is flying toward you.
- If he reaches into that same magic rune and holds his hand there for a second or two, he is about to summon his blood rain. You can punish this attack with one or two hits from behind, but once the blood actually starts raining, you need to step back to avoid getting caught in the damage cone.
- Almost all of Mohg's melee combos are three hits long, so make sure you aren't trying to punish or guard counter until the very end of the sequence. Be even more careful of the ground stab, which has a second hitbox when he pulls the spear out of the ground.
- The most punishable attacks are the overhead slam and forward thrust. Both can be dodged by simply rolling into him before the weapon makes impact, allowing for a few hits before he follows up.
Upon taking 15-20% of his health in damage, Mohg will thrust his spear into the air and do a diagonal slash, which can be avoided by simply strafing to his offhand side or behind. Even if you dodge this attack, a blood ring will appear around your character. He will do this each time he loses 15-20% of his health until you have three rings on you. At this point he will activate the rings, causing three instances of highly damaging bleed that restore Mohg's health. You basically need to chug flasks between the instances of bleed to survive, then get ready for phase two against the newly refreshed Mohg.
There seems to be an opening here to kill Mohg before he has the chance to activate the blood rings and enter phase two, but the timing is tight. You need to get him down to about 60% of his total HP to the point where he will activate two of the three rings. Activate all your damage buffs, use Mohg's Shackle to stun him, and then start laying into him with your most damaging combos. If you can burn his remaining 60% health before he can break the shackle and cast the final ring, you can end the fight before phase two. Some things that can help: a Bleed weapon, Ash Summon, damage-enhancing items, Flask of Wondrous Physick buffs, and damage-focused accessories.
You can also use the Purifying Crystal Tear, found on the Altus Plateau, to negate the effects of Mohg's curse entirely and remove the rings from yourself—though he will still go into Phase 2 regardless.
Even if you don't have the damage or execution required to kill Mohg in phase one, it is still a good idea to try and maximize your phase one damage because that will mean he starts with less health in phase two, meaning less time you have to phase this hellish foe. In phase two, Mohg grows wings, his attacks gain even more bleed and magic damage properties, and he starts mixing in some new attacks (and, of course, Mohg's Shackle will no longer stun him).
His base moveset remains mostly the same, except now his melee swings fling blood that deals extra damage, and he likes to fly around in the air when casting spells. If you are using a shield, you just have to eat this damage and stay on top of health management between his combos. He seems to be a bit more unrelenting here as well, so it will be harder to create distance and heal when needed.
Some new additions: the thrust attack now has a second instance of damage where Mohg twirls the spear to fling blood, and the explosion after the ground stab is bigger and even more damaging, so strafe around and get away from it by any means necessary.
He also likes to mix in a long-range, multi-hit thrust attack when you are far away, which he telegraphs by leaning back with both hands on his weapon, slightly flapping his wings, and then dashing forward. It seems best to dodge to the side when you see this one coming. The same goes for his uppercut into ground slam, which ends in a similar explosion to the ground stab. It is tempting to try and punish, but it is best just to stay back.
That all sounds pretty dangerous, so when do you hit him? As usual, the move is to wait for the overhead slam attacks. If you stand outside his melee range, you can tempt him into two highly punishable attacks: his long-range slam, where he holds his spear by the very end and slams it down in front of him. Dodge roll forward, and you can get a few easy hits. There is another variation of his where he jumps into the air before slamming the spear down; similar concept, similarly punishable.
