I beat Margit the Fell Omen on my first try… in co-op. With two players we easily divided his attention, stayed out of range of his giant magical axe attacks, and whittled him down with powerful magic when his back was turned. Ha! He talked tough, but he went down like a chump. Full of confidence, I went back to fight Margit the Fell solo… and got trounced at least a dozen times.
I was fighting tired, without really focusing on learning and reacting to Margit the Fell's moveset. And like a lot of Souls bosses, Margit demands that kind of mastery. He's fast, hits hard, and has an extensive arsenal of moves to hit you with at both close and far range. You're never safe in this fight, and the windows to sneak in hits are very small. This is one exciting, tough fight.
If you're having trouble taking down Margit, I've been there, so I can help. Here are the attack patterns you need to learn, and some tips to make the fight easier.
Margit the Fell's attacks to watch out for
Tail swipe - If you're standing right behind Margit after he finishes an attack combo, you'll be safe for a few seconds—and then he'll probably do a whirling attack to hit you with his tail, knocking you down. It comes out fast, so be ready for it.
Magic blade - For the first half of the fight, Margit primarily attacks with two weapons: the staff in his right hand, and a glowing magical blade (which still deals physical damage) he summons in his left. The staff attack is a relatively slow, heavy hit, but Margit summons the sword to deliver a fast, close-range combo, even while he looks like he's in a recovery animation from the staff attack. This is the attack that gave me the most trouble, because he always used it when I thought I had an opening. To be safe, don't try to get in more than one attack before dodging away or putting up your shield.
Blade throw - When you back away to heal, Margit loves to summon two of those magic blades again and throw them at you. Every time you get some distance to drink from your flask, strafe side-to-side so he can't hit you. They're easy to dodge if you're ready for them.
Combos - The most dangerous thing in this fight is Margit's unpredictable combo patterns. Sometimes he'll swing once or twice, and other times he'll chain a spinning attack into a multi-hit sequence. Don't try to attack him: just block or dodge backwards, if you think you can get out of range of the staff. I think blocking's easier, since he'll swing multiple times in a row. Generally you want to keep your distance and wait for his hammer jump, which gives you a much easier opening.
Hammer jump - This is Margit's heaviest hit but also the best window for you to get in a couple hits if you dodge properly. Once his health is at about 60%, Margit will summon a giant glowing hammer with his left hand. At close range he'll swing it at you, but when you get some distance he'll instead do a leaping overhead attack. You want to bait this out, then roll towards him at the last moment, dodging through the impact and coming to your feet right in front of Margit. This will give you a couple seconds of safety to wail on him.
If you're not using magic, convert all your flasks to Crimson Tears
This is a small thing, but it'll help you go into the fight with more healing power in your back pocket. At a Site of Lost Grace you can balance your flask uses between Crimson Tears (HP) and Cerulean Tears (FP). Set all four to Crimson Tears so you have four sips of lifegiving liquid.
If you're relying on magic attacks to deal damage, though, you'll need at least one flask of Cerulean Tears to refill your FP. See if you can get by with one, and if you find yourself running out of FP before Margit's done for, kick the balance up to a 50-50 split.
Use a Spirit Ash to distract Margit
Spirit Ashes are Elden Ring's version of summonable NPCs like Solaire, but this time they're items you acquire and can reuse throughout the game. You can purchase two ashes from Merchant Kalé near where you enter Limgrave: the Lone Wolf Ashes and the Noble Sorcerer Ashes.
The Lone Wolf Ashes are good for this fight, because they spawn three wolves who can keep Margit distracted for awhile. You're not counting on them for damage: they just need to stay alive long enough to pull aggro away from you so you can rush in and get some hits.
Magic users: Attack with Beast Claws or Glintstone Stars
Both of these spells hit Margit hard, and used in combination with the Lone Wolf Ashes, you'll be able to deal him a lot of damage while mostly avoiding his ire. If you want a real one-on-one fight, using magic is trickier, but definitely doable.
Beast Claws is a starting spell for the Prophet class and scales on faith. You can charge up the spell for increased range and damage, which is a fantastic move—but you're going to have to be really careful with how you use it, because Margit has both jump attacks and throwing knives to hit you at range very quickly. If you get a feel for Margit's range, you can stand just outside of it, charge Beast Claws, and release right before he jumps at you to get in some damage.
Don't try to charge up this attack when you're in close—Margit is way too fast and will nail you with a combo before you can release it.
Glintstone Stars is a sorcery that creates three magic missiles which will home in on Margit automatically. You can acquire it from Sorceress Sellen, who appears in the Post Town Remains on the eastern edge of the map once you've killed the Pumpkin Head Boss. To find Post Town Remains, cross the large bridge and look for some ruins filled with large plants (heads up, one of them is going to shoot magic beams of light at you). There's a stairway amid the ruins that leads down to the boss chamber. When casting Glintstone Stars, make sure to keep a safe range. Again, you don't want to get nailed while you're stuck in your casting animation.
Gear up with the Crucible armor set
The strongest and heaviest armor available in the network test will give you far better defense than the starting gear of most of the classes, particularly the Prophet or Champion set. The Crucible set is easy to find, and if you put even a few leveling points in strength, you'll be able to wear it while maintaining a medium equipment load.
To find the Crucible set, head to the east side of Limgrave and look for the carriage being hauled by two giants, with a procession of knights and undead trailing along behind it. It's hard to miss. Kill the followers first (drive-by attacks while mounted make this easy work), then take the giants down one at a time by getting in a hit, dodging a foot stomp attack, and repeating until they're both dead. The chest on the back of the carriage will then be accessible.
Slow Margit with the Dragonscale Blade
One of the most powerful weapon arts in this early bit of Elden Ring is a skill called Hailstorm Sword attached to the Dragonscale Blade. Hailstorm Sword calls down a bolt of ice-lightning (lightning-ice?) that makes the weapon do both types of elemental damage for about 20 seconds. But the important thing here is that if you can get in enough successive hits on Margit quickly enough, the ice will apply a chilling effect that significantly slows his movement. Because he's so fast it's hard to pull off, but if you manage it, Margit will be much more manageable for a bit.
The Dragonscale Blade is a great weapon for faith builds, because it scales on strength, dexterity, and faith. You can get it by killing the troll boss in the Limgrave Tunnels mine, which you can find at the northern tip of the lake-slash-swamp in the center of the map.