You'll have to fight a total of three bosses at the same time to completely finish up the first part of the Dark Souls 2 DLC. We'll show you how to fight each enemy one-on-one, and explain the correct order to take them out in.
Graverobber, Varg, Cerah fight
You'll be attacked by both Varg and the Graverobber as soon as you enter the boss arena, so be ready for battle. Varg wears very heavy armour and makes use of a massive weapon and a shield. This makes him relatively slow, and so there are plenty of opportunities to give him a wallop after each of his attacks. Make him your priority, but do hit the others if they happen to be closer.
As for the Graverobber, he makes rapid attacks with a pair of swords. If you don't have a big weapon capable of knocking him down, you'll have to keep circle-strafing around him and use a shield to avoid the worst of his damage. When you spot a gap in his attacking patterns, get stuck in yourself - just make sure you have a speedy weapon to hand.
Should you find yourself fighting both Varg and the Graverobber at the same time, back up and wait until Varg has missed with an attack. When that happens, hit Varg quickly and then move away fast before the Graverobber can get started. Just keep this dance up, keeping your focus on surviving the encounter, rather than finishing it.
Cerah attacks with a bow from distance, but you should focus on killing the first two enemies before tackling him. When they're dead, close in on Cerah, but be prepared for your opponent to switch from the bow to a sword.
Wait for one of Cerah's lunging attacks, then get some damage in of your own while your opponent is recovering. You should be able to get at least two attacks in during these combat opportunities. If you find yourself struggling with health at any point, dart over to one of the rocks or walls and use a healing item quickly.
When all of the bosses are dead, keep walking through the cave, take the Blackweed Balms from the next room on your left, and make sure you loot the nearby chest as well. Next, jump down through the gap in front of you to find yourself back in Shulva, Sanctum City.
You can find help for all of the Crown of the Sunken King bosses from the first page of our guide.