Old Dragonslayer

The Old Dragonslayer is an optional boss in Dark Souls II.

General Information
The Old Dragonslayer can be found in the Cathedral of Blue (2880 HP). He is opposite to the Dragonrider and is accessible after raising the lever to lower the drawbridge. The Old Dragonslayer's moveset is nearly identical to Dragon Slayer Ornstein's with the exception of dark magic attacks.

Summoning
Masterless Glencour can be summoned from a ledge just to the right of the Dragonrider's arena. A fearless tank knight wielding a greatsword and a shield, Glencour will immediately rush the Old Dragonslayer after stepping through the fog gate, and continue to distract and inflict moderate damage throughout the battle, making him an invaluble ally to those having trouble conquering the Old Dragonslayer in a one-on-one situation.

Strategy
The fight is very similar to the Dragonslayer Ornstein and Executioner Smough battle without Executioner Smough. There are slight differences in how the Old Dragonslayer fights compared to Dragonslayer Ornstein. An example would be that the Old Dragonslayer uses a dark magic attack, while Dragonslayer Ornstein did not. Otherwise, Old Dragonslayer has the same sort of movement and similar attack patterns as Dragonslayer Ornstein in the original Dark Souls should the player slay Executioner Smough first. If one takes his time fighting with him, he will shoot three dark magic orbs to the player from the tip of his spear.

Blocking until the Dragonslayer misses an attack may prove to be beneficial to the player, as well as backing away when he begins to cast his magic attack. Using a bow or crossbow may result in being able to stun-lock him by shooting him in the head. The Old Dragonslayer is weak to magic and is also vulnerable to lightning-based attacks. Sorceries can work out to be a viable tactic, if the player is able to anticipate his movements. Magical augmentations work very well against him.

Just as The Pursuer's cursing lunge is unblockable, the Old Dragonslayer's dark impaling lunge is the very same. It is predictable, and has some starting lag, so evasion is paramount to not suffering the massive damage of this move.

One highly effective strategy is strafing counterclockwise (player's right), as most of his attacks come from his right, making it especially hard to hit the player. It is possible to not have to block using this.

Boss Information
Attacks Charge (Fast Lunge): While the player has some distance between him, he will kneel down and charge at the player lunging his spear towards the player. Can knock down players if it connects. Blockable, at the cost of moderate stamina loss.

Jump Strike: Leaps into the air and slashes his spear on the ground. Hits hard, oftening stunning players who do not dodge in time, and the attack inflicts a fair amount of stamina loss if blocked.

2-hit Combo: He swings his spear horizontally, twice in a row. Connects twice, but can be blocked.

Lunging Uppercut: Lunges his spear forward and afterwards proceeds to perform an uppercut

Impale: Grips his spear with 2 hands and lunges it at the player. Unblockable; if the attack connects the player will be impaled, lifted up in the air, and thrown back down. This attack is similar to 'super' Ornstein's lightning impale technique in Dark Souls. Has a defence boost for a few seconds during the attack.

Dark Bonzai: His body will emit a dark aura, then he will proceed to jump into the air and land on the ground, exploding in a dark AoE (area-of-effect) attack. Very similar to 'super' Ornstein's bonzai move from Dark Souls, except this one explodes in dark energy, and not electricity. Evading this attack entirely is highly recommended.

Dark Barrage: The spear glows in a dark aura and he lunges it forward, and doing so will fire off several dark bolts at the player. It is highly recommended to evade the bolts entirely, if nimble enough, or block the attack with a shield that provides both decent stability and dark defence.

Trivia

 * The Old Dragonslayer is reminiscent of Dragon Slayer Ornstein from Dark Souls.
 * The Old Dragonslayer uses a dark attack similar to Smough's special attack and Ornstein's after defeating one before the other in Dark Souls.