Eidolon

Eidolon is the oldest and most powerful of the Serpent Rider demons from the Heretic/Hexen games and the final boss of Hexen II. Eidolon, seemingly, makes his first appearance in Hexen's epilogue, moving a Korax's figure on a chessboard. Eidolon has conquered the world of Thyrion and has appointed control over Thyrion's four continents to his dark generals, the Four Horsemen of the Apocalypse. The player must battle all Four Horsemen (along with all of Eidolon's lesser minions) before Eidolon himself can be confronted.

Eidolon's appearance is that of a red demon-type creature with goat legs. When the player enters his arena, Eidolon will burst through a wall and jump down, letting out a loud roar as lightning strikes all around the arena.

He attacks the player at a distance by hurling several large balls of lighting at the player that have limited tracking ability. In melee he will launch the player up into the air and away from him.

Once he has taken a certain amount of damage, Eidolon brings the Chaos Sphere into the battle, and uses its power to make himself grow. At this point, he loses his original attacks and gains new ones; the ability to hurl a series of extremely fast fireballs that do over 100 damage each, and to project a devastating stream of flame at the player at medium range. Giant Eidolon will also be invincible as long as the sphere is present as he uses it to heal himself when he takes significant damage. Hence it should be destroyed as quickly as possible so Eidolon can be hurt.

When defeated, Eidolon shrinks back to his normal size and his body bursts apart in an explosion of gore and brilliant light, and Thyrion is freed from his control.

Giant Eidolon is unable to hit a player directly under his lower legs with any attack, though the game will try to push the player out. Hence, if the player can remain under Eidolon's legs, they can defeat him with no risk to themselves simply by hacking at his feet repeatedly.

In the expansion for Hexen II, Portal of Praevus, the player can play as the Demoness, a minion created by Eidolon before he was slain.