11 of 21
11. Iron Golem:
The Iron Golem stands at the top of Sen's Fortress, one of the more frustrating areas in the game. With this fight, it's best that you don't bother blocking, focusing on learning his attacks and when to dodge them. Attacking his legs will cause him to fall down for a bit—make sure you're not under him when that happens—so have at it when he tumbles. This fight, like the Firesage, takes a bit because of the Golem's health. Be sure to be patient, don't get greedy or it'll cost you big time. If you want to speed up the fight, lightening-based weapons will do more damage to the golem.
Summon? Yes, if possible.
12 of 21
12. Capra Demon:
Ugh. Fighting Capra Demon is a royal pain, mostly because the battle takes place in an arena barely bigger than a closest. He has two dogs he sends after you—take them out first in whatever way you can. Killing them is key here. Don't bother with the demon until they're dead. Once that's done, roll past Capra, and go up the stairs. Either arrow him to death or stab him when he follows you and then drop down, run back up the staircase again, and repeat until he's dead.
13 of 21
13. Centipede Demon:
Centipede Demon is one of the few fights in Dark Souls that's neither fun nor interesting. It's just dull and tedious thanks to the centipede's wide swipes and the fact that this fight takes place in a cave where stepping on lava will gravely injure you (imagine that). Once the fight starts, run to the right until you reach a rather sizable chunk of land. The bug will follow you. Once you're here, just learn the pattern and focus on dodging a lot and stabbing the monster immediately after it swings and misses you. Try not to get hit; its swings hurt. If you've got a long-reaching weapon that deals some nice damage, now is the time to use it.
Summon? Yes, if possible.
14 of 21
The Hydra fight is technically skippable but it's pretty fun as well. Kill all the golems in the surrounding area first and then run toward the lake, dodging the hydra's water blasts by seeking cover. Once you get close enough use a shield to block the hydra's lashes and attack the monster yourself when it's recovering. Don't bother with ranged attacks.
15 of 21
15. Sif, The Great Grey Wolf:
Sif is quick and hits hard but his moves are telegraphed so spend some time learning his patterns—when he jumps, charges—and then go at him when he's recovering stamina. Beyond this being a grueling fight that drags on for a bit, it's also pretty heartbreaking, as Sif starts to limp and look all sorts of pathetic as the battle draws to a close. Don't let your guard down though. He still packs a wallop.
Summon? Yes, if you can.
16 of 21
16. Hellkite Dragon:
Hellkite Dragon is another fight that's completely optional. However, given just how much trouble this bastard gives you, it's worthwhile to pester him back. The first time you meet him, he's sitting over a bridge. Now, what you can do here—and you should if you're playing melee—is find the path to getting under the bridge and then go there with a bow and a lot of arrows. You'll see his tail hanging down. Shoot a bunch of arrows at it until the tail falls off (this can take awhile) and you get one of the most powerful weapons you can get early in the game. Don't bother trying to kill him with arrows or fighting on the ground. The reward isn't worth it. Just run past him and get to the bonfire and you don't have to deal with him anymore.
17 of 21
17. Gravelord Nito:
Yuck. This one's a struggle, especially if you don't have a divine weapon to kill the skeletons at the start (they'll resurrect throughout the fight to pester you otherwise). The thing to worry about here is Nito's shockwave attack. If he curls, it's time to run away as fast as you can. Otherwise, his attacks are easy to dodge. If you've got firebombs or, better yet, fire weapons, use 'em here. They can be particularly helpful if you weren't able to put down the skeleton minions.
Summon? Yes, if you can. Cooperators can distract the skeletons for you.
18 of 21
18. Chaos Witch Quelaag:
Quelaag is the kind of boss that begs for you to summon a cooperator, NPC or otherwise. If you can do that, I highly recommend it as having someone distract Quelaag makes this fight go from feeling impossible to being somewhat bearable. If you want to be a badass about it—or you just can't summon anyone, which was my situation—accept you are going to die several times. Quelagg has about a dozen attacks and most of them hurt. Spend three or four lives learning her attacks. Don't bother with trying to understand a pattern; her attacks seem randomized. The best thing you can do is bait her to do her lava vomiting attack (yuck) and then roll into her side and strike. Good luck.
19 of 21
19. The Four Kings:
This is more time trial than boss fight. Take a stamina booster and hope your weapon swings fast and true. The battle starts with one boss who floats around in the darkness. Race toward him and put him down as quickly as possible. Three other kings will show up at different intervals. There's no clear strategy here except be fast. Summoning will help here as well.
Summon? Yes, if you can. Summoning the NPC witch or a player for The Four Kings can turn this fight into a breeze.
20 of 21
20. Gwyn, Lord of Cinder.:
The difficulty of this battle depends entirely upon your ability to parry enemies. If you're particularly bad at parrying—like most people who play Souls are—this fight is ridiculous. Gwyn is strong and fast, and his moveset doesn't appear to have a pattern of any sort.
Don't bother with ranged battle; he can cross the room quickly and skewer you with ease. You're going to want to stick close to Gwyn and have a heavy weapon that staggers him. If you don't have a heavy weapon and can't parry, go get one. Also: consider summoning. No one will shame you for getting help with this fight.
21 of 21
21. Dragon Slayer Ornstein and Executioner Smough:
Ornstein and Smough are probably the most recognizable bosses in Dark Souls. When folks talk about the memorable moments in the game, taking on both Ornstein and Smough at the same time is probably their favorite encounter in the game or the moment they gave up. However, for all its infamy, this fight is far from impossible. It's just that being double-teamed gives the appearance that this is super difficult, when it's more than manageable if you divide & conquer. Kill Ornstein first. Dance around the columns, strike him as soon as you dodge his jab. Once he's' down Smough consumes his power and becomes electrified. He chases you around the hall. Run from him and pelt him to death with your arrows. This takes a long time but it gets the job done.
Summon? Maybe. I'd recommend seeing if you can beat this on your own and only summoning if you just get really frustrated. It's supremely satisfying to take these two down on your own.