This is probably the first challenging boss of the game, simply due to the fact that you will be fighting two of them at one time at some point in the fight. If you have the Drake Sword from the red dragon, then this fight will be a little easier. If you can get a shield with some fire resistance, it will also help (Heater Shield or Hollow Soldier's Shield are two ideal ones). The fight begins with only one Gargoyle to fight. The most dangerous attacks are its overhead swing and its tail swipe, both of which can be easy to dodge if you know they're coming. The best plan of action is to stick close to the Gargoyle, with a shield up at all times. Keep taking shots at it when it swings with its weapon; if you cut off the tail, you will get the Gargoyle Tail Axe. It's best to keep the first Gargoyle at where you entered the battle, as you will see shortly. When you get the first Gargoyle's health to 50% or lower, a second one will spawn at the far end (from where you entered) of the roof. The second Gargoyle has a new attack, which is its most dangerous one; it breathes fire that fans most of the area in front of him. It will use this attack a lot, especially if you stay far from it, so make sure you're always wary of where the second Gargoyle is located. You should concentrate on the first Gargoyle until its dead, then you can go after the second one. One good strategy is to get the first Gargoyle's health to just before the second one spawns, then wail on the first one relentlessly until you finish it off. Note that the second Gargoyle does not have a tail when it enters the battle. You can summon NPCs to help you (you must be alive); Solaire's sign is in front of the fog gate and Lautrec's sign (must open his cell first, needs a Mystery Key) is behind the first ladder, on a ledge proceeding up to the fog gate.