21 of 30
21. The Old Dragonslayer: The Dragonslayer, a callback to Ornstein from the first game, is pretty hard. He's swift, difficult to hit, and his attacks do a decent amount of damage. You might be tempted to hide behind the pillars around the room but don't; he just slams through those and damages you anyway. Focus on rolling around him and attacking him once he strikes and misses. If you can summon for this fight, I highly recommend it.
22 of 30
22. Ruin Sentinels: The Ruin Sentinels are aggravating as hell. There are three of them and they're all quick and powerful. Luckily you only have to fight one of them at the beginning. Once that one is down, the other two come after you at the same time. It's really, really helpful to have a summon in this area, preferably a player since the NPC summon outside of the fog gate has weak health. Lightning will help a lot in this fight as the Sentinels are weak to it.
23 of 30
23. Belfry Gargoyles: Folks who have played through the first Dark Souls will have no trouble remembering the original Gargoyle fight. Well, this is essentially that fight but the gargoyles are on steroids and there are five of them, not two. Oh, and there's no summoning. This fight is optional but if you want to take them on for a decent souls reward, lightning and rolling will likely serve you best here.
24 of 30
24. Velstdat, The Royal Aegis: Velstdat hits hard and is pretty fast, so what you need to do is focus on learning when to dodge his swings and then attack him. I'd recommend getting him to clear the room of pillars so you have more space to fight him in. You can also technically parry him but the risk isn't worth the payoff.
25 of 30
25. Nashandra: The final boss for Dark Souls 2 is by no means a cakewalk but she's also surprisingly easy to defeat for the final boss of the game. She has a huge scythe that she uses to damage you and laser vision that can hit you from a distance, as well as some orbs that constantly circle her and will curse you if you get too close. What you can do here is simply arrow her to bait her to come to you and then attack her after dodging her scythe swing. Once her orbs catch up to you both, pull back and do the same thing over and over until she's dead.
26 of 30
26. Aldia, Scholar of The First Sin: Aldia is an optional boss that was added in with the Scholar of The First Sin update. He's also a bit of a pain. While the fight itself isn't too difficult, it can become that way if you're impatient. Aldia teleports around the arena and almost immediately wraps itself in flames that will do damage to you if you try to attack it. You have to reach it soon and attack quickly to avoid damaging yourself while also avoiding Aldia's red glowing balls of dooms that it sends after you. Be patient, don't get greedy, and be willing to devote a lengthy chunk of time to this fight and you'll probably be fine.
27 of 30
27. The Rotten: Remember our friend Smelter Demon? Okay, imagine him bigger, and nastier, and harder to kill…and surrounded by firepits. Yep. That's this fight in a nutshell. It's long, difficult, and you will probably die a lot with or without summons, just accept it. This battle requires you not only to memorize the boss's moves but also the layout of the battleground itself. One wrong step into a flaming pit is just as deadly as getting hit by this jerk. Roll a lot, try and hit him on the side, and then roll away (hopefully not into a firepit).
Summon? Yes. Having someone to distract The Rotten is an invaluable tactical advantage.
28 of 30
28. Vendrick: Vendrick is a right old bastard. The key to this fight, more than anything else, is preparation. Do not bother with this fight unless you have some giant souls on you; they lower Vendrick's ridiculous defense rating. The more you have, the weaker he is. Here's a list of where to find them. He's quite slow and easy to dodge, so once you have a decent number of giant souls this fight is pretty easy. Getting them is a pain though.
29 of 30
29. Looking Glass Knight: This fight is a tough one. Not only does the knight swing hard and far, but he also has a shield that will block your attacks even when he's not in blocking pose and, here's the kicker, he can summon ONLINE PLAYERS to fight you. That's right. Not just an NPC, but another player, which makes an already difficult fight an absolute nightmare. The best thing you can do here is take the game offline and use the NPC summon. The boss will still summon minions to attack you but they'll probably be less difficult than another player. Learn the knight's attacks and dodgeroll to his right, open side. Hit him twice and then roll away. Be sure to look out for his nasty electric attacks; one of them sends homing energy balls after you.
Summon? Yes, but take the game offline and summon the NPC (Benhart of Jugo). Trust me, you don't want to fight another player during this battle.
30 of 30
30. Throne Watcher and Throne Defender
This fight is essentially Dark Souls 2's answer to Ornstein and Smough. You're fighting two ultra powerful figures at the same time, one of them slow and armored, the other swift. This fight is particularly difficult because 20 seconds after you knock one of them down, the other will revive them. So what you need to do is summon, summon, summon and be quick. Summon both the NPC and, if you can, another player. You have to be fast and powerful to take them both out. Good luck.
Summon? Yes, don't be a hero. Just summon.