An example would be that the Old Dragonslayer uses a dark magic attack, while Ornstein uses lightning. There are slight differences in how the Old Dragonslayer fights compared to Ornstein. The fight is very similar to the Dragonslayer Ornstein and Executioner Smough battle without Smough. In Scholar of the First Sin, Devotee Scarlett can be found at the bottom of the stairs leading up to the spear-wielding Heide Knight and the Guardian Dragon.

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 invaluable ally to those having trouble conquering the Old Dragonslayer in a one-on-one situation. Masterless Glencour can be summoned from a ledge just to the right of the Dragonrider's arena. It is unknown if this is the same Dragonslayer encountered in Anor Londo in Dark Souls, or perhaps an imposter using Ornstein's influence and equipment, or something else entirely. The Old Dragonslayer is a mysterious figure with little to no available information on him.

The Old Dragonslayer's appearance and moveset is nearly identical to Dragon Slayer Ornstein's with the exception of dark magic attacks, as well as his armor being black instead of golden.

Dragon slayer wiki old school