Havel the Rock was a bishop of the Way of White. He was a close friend of Lord Gwyn and, by extension, Kingseeker Frampt. His hatred towards magic and Seath the Scaleless made him develop the miracles Magic Barrier and Great Magic Barrier. His gear also has high magic resistances to combat magic threats. In an indeterminate time before the event of the game, he became Hollow and was locked in the watchtower for his own good.
Inside the Undead Burg watchtower. The entrance is on the Darkroot Basin, near the Crystal Golem area. You need the Watchtower Basement Key to open it. If you have the Master Key, you can open it from the Undead Burg side. The door is on the bottom floor of the tower with the Taurus Demon boss fog.
Havel The Rock is a very difficult enemy when first encountered. He wields the Dragon's Tooth and will kill most players with one hit. Acquiring the Drake Sword prior to engaging him is not a necessity but for melee strategies will make the fight a lot faster than using any of the starting weapons or standard drops to this point in the game.
To be safe you can run back up to the previous level when he starts chasing you instead of moving down to his level. Havel can be a difficult opponent for low-level characters, and this allows you to perform a retrieval without aggroing him again if you decide to leave him until later.
If you have a decent shield, his attacks will not break your guard. With 20 endurance and the Eagle Shield, you can block his strikes and attack while he recovers. The simplest strategy but requires you to come back later once you have acquired a medium or heavy shield with perhaps 60+ stability.
Parry Riposte strategy
Wait until Havel finishes an attack and then run in front of him. Stand there with shield lowered and parry-riposte every attack (video demonstration). If you equip a small shield like Cracked Round Shield, the time window for parrying increases compared to when using larger shields, thus giving you a larger margin for error and probably making this the easiest and fastest method for disposing of Havel. Once rispoted, immediately target Havel again.
As he will probably kill you in one hit anyway, you can equip the Red Tearstone Ring and let the Hollows outside reduce your HP to a level in which the ring will be activated, this will reduce the number of times you need to riposte Havel and make this strategy safer.
This strategy is based off avoiding his attacks, either by strafing or rolling through them, to get behind him and perform a backstab. Light armour (<25% capacity) is highly recommended if not required for this strategy, and you should engage him in the middle of the room to give yourself more space.
If you are strafing his attacks it is best to have a shield raised just in case. Stay right up against him and keep circling him until he uses an attack and allows you to get behind him. Use lock-on for this strategy.
If you are rolling through his attacks, stay a little further back and do not lock on. When he uses an attack, roll past and get behind him.
If you are a mage, you can dodge him pretty easily and hit him with Soul Arrow, the only problem is when he raises his shield, in this case just hit him with fireballs.
In this strategy you will need a bow, about 120 arrows, and patience. Have him follow you outside, he will only chase you to the bottom of the stairs before turning back to go back to his position. Shoot him in the back as many times as you can, if timed right you can get 4 arrows off before he gets out of sight. Step back inside to get his attention and repeat.
Fall Damage Tactic
Once Havel starts chasing you, run back up to the previous floor then run up the next set of stairs to just before you can no longer jump off. You must wait here until Havel is very close to you but has not started his attack yet, and then jump off. The fall will deal some damage, but more to Havel as he follows you. Run back up and repeat. You should only need to refill your estus flask once, and you will have more than enough time do this when you're at the top of the stairs. Roll once you hit the bottom to give you a good head start on running back up the stairs (less than 25% equip load recommended).
This is a very easy way to kill Havel, and can be done even at low skill levels. The one thing to remember is to wait until Havel gets right up next to you, because if you jump off when he is too far away from you he will simply walk down the stairs and attack you.
Poison Mist tactic
Poison Dagger / Dung Pie Strategy
Through the door Strategy
If you make your way to the bottom of Darkroot Basin, you can go up a hill that leads to the tower Havel is in. Make sure you don't open the door leading into the tower. You can actually hit Havel from outside the door while it's closed; however, this works both ways, as he can hit you as well. Get in one hit and then dodge to be safe. With Halberd +3 it takes maybe ten minutes or less to kill him this way.
- You can also kill him with the door open, as he cannot go down those stairs leading to Darkroot Basin. Keep luring him into the doorway and attacking him that way. Be careful though, as stated as before he is still able to hit you.
Ring of Fog Strategy
Equip Ring of Fog to lower Havel's detection of you and make your way down to the lowest tier of his tower. Walk once he is in view and make your way down. Slide off the stairs at a safe falling distance and walk all the way around until behind Havel. Backstab him, then run up the stairs until about the first level nearest the door. He should lose interest and head back to his starting position. Repeat.
Plunging Attack Strategy
Because Havel is so slow, he can be lured towards the bottom of the stairs, where he can be tricked into attacking the player from the side (rather than climbing the stairs). After he begins his swing, roll up the stairs. He should move along the stairs if you don't go too high. Once you're a few steps higher than his head, perform a plunging attack. At sou level 20, it takes 3-4 attacks with a +5 Uchigatana.
Alluring Skulls Strategy
You will need some Alluring Skulls. You can go through the door at the bottom of the tower from Darkroot Basin and throw an Alluring Skull at the door hinge from outside on the stairs (or closer if you keep missing the door), but not too close. Make sure that Havel either goes straight to the door or straight behind the door and not at you. When you see that he's ignoring you, two hand your weapon and wail on him, he won't swing back. When he raises his weapon, back off, let him retreat behind the wall, then repeat. With the Drake Sword, three Alluring Skulls should do, but again bring more in case you miss the door.
Dragon Head Stone Strategy
The Dragon Head Stone is easy to obtain as early as the start of the game. Should one have it, they can simply clear out the nearby vicinity of hollow soldiers and lure Havel to the "ground floor" of the tower he is in. He is scripted to not exit the tower so players can exploit this to retreat/ heal or make some distance between them and Havel.
The Dragon Head Stone's flame breath have more than enough range so that the Havel's attacks can be dodge by a simple back step or side roll. Given enough time, Havel will be down regardless of the player's level. The key in this strategy is to keep a distance between you and Havel that is sufficient enough for the flame breath to hit him and at the same time far enough for you to be safe from the Dragon's tooth reach
Leash point Strategy
Havel is not technically able to leave the tower. His "Leash" point occurs right around when you get him to one of the doors that exit the tower. He will however carry out a melee attack that he started to perform and chase you down to execute it. Using this to your advantage, lure Havel up to the exit of the tower that leads back to the bonfire in the Undead Parish. Eventually he'll decide to commit to taking a swing at you (this can be provoked easier by using a ranged attack on him) and he will follow you down the stairs. Once he does his swing, run in front of him and body block him to prevent him from getting back into the tower and start pummeling him with melee attacks. He will single mindedly continue trying to get into the tower, and will not attack you until he has made it back in. You can either beat him to a pulp, or use this knowledge to continually backstab him as he tries to get back in.
There is an open ledge close to the bottom of this staircase! Do not let Havel fall off the ledge, or you will lose the Havel's Ring loot for the rest of your playthrough! Reloading does not make the ring drop at his spawn, unlike most other NPC's.
This works best if you have both the doors in the lower watchtower shortcut to the Darkroot Basin open. Starting from the Undead Burg bonfire with the ladder shortcut to the Undead Parish, leave the room and sprint past everything (this part is very important!). You should have the enemies chasing after you, just don't look back. Sprint down the stairs and around Havel, and out the door he was standing next to. Havel should follow you out the door and to the first step, and stop, running into an invisible wall. Some of the enemies who were chasing you should follow, and get stuck behind Havel, in the doorway. This prevents Havel from backing up into the room, leaving him open to any spell or arrow you want to throw at him; just be careful not to kill the soldiers blocking him.
If you have over 20 Faith you can also use the Lightning Spear Miracle to take Havel down. You basically inch your way down the stair case until you can lock on to him and carefully fire off spears. He should fall within 3 or so hits, you will have to dodge an attack or two but it is a surprisingly easy way to dispatch this colossus.