Eligor

Order of Ecclesia
Eligor (エリゴル) appears in a section of Dracula's Castle known as Arms Depot "Cry in the Night" as the game's 12th boss. He guards one of the three Cerberus glyphs. If you underestimate his size, the battle will end quickly with you underneath his hoof, impaled by his crossbow bolts, or even on the end of his blades. Eligor is a demon in the form of a giant centaur knight with a giant sword, bladed tail, & crossbows on his shoulders/hips. This battle has four phases: attacking his front legs & the crossbow in that area, carefully moving underneath him and avoiding his crossbow bolts, attacking his hind legs & the crossbow in that area, & attacking the eye on the back of his head. You do not have to destroy the crossbows on his body, but it is highly recommended, because when you are crossing over to his back side, & when you are trying to attack his head, they will relentlessly fire off arrows at you. His weak points are his eye, and any ruby dots you see along his body. He is weak to blunt and lightning attacks, so Glyphs such as Melio Macir, Lapiste, or Globus are very useful against him. Using Globus takes a bit more time, but once the turrets are destroyed, you can switch to a melee glyph to use on the legs to gain easy access to his back should you fall. It should also be noted that the eye on the back of his head is not weak to blunt attacks, but instead slash attacks. When fighting the eye a slash glyph with the Wind Ring equiped will deal a decent amont of damage. When on Eligor's back, it is very important to read each of his attacks, as he will attempt to knock you off. To get back on, simply attack the gems on his legs again, which will take less damage to shatter than before. An alternate way to fight Eligor is to use Magnes and Redire to fling yourself onto his back after taking out his front knees, although this is difficult to learn at first.

Eligor is based on the demon Eligos (also known as Abigor or Eligor) from the Ars Goetia. A Duke of Hell, Eligos discovers hidden things, knows the future of wars and how soldiers should meet, and attracts the favor of lords, knights and other important persons. He is often depicted as a knight on horseback wielding a lance, scepter, or a serpent, and sometimes as a ghostly rider on a skeletal steed.

After beating the game and unlocking the second Boss Rush Mode, you can use the Volaticus glyph to fly up and over Eligor's head at the beginning of the fight. The easiest way to get over his head is to wait until he attacks to fly over. An alternative method is to equip the Wind Ring and two Melio Ascia glyphs and attack the back of his head from there. While using Volaticus won't use up most of your MP, the Melio Ascia glyphs will, so if you run out, fly around to recharge your MP while avoiding all of Eligor's attacks at the same time. It will end quickly that way. Eligos is probably the largest enemy in a Castlevania game.