Sacred Beast

The Sacred Beasts are 3 powerful monsters released in the Shadow of Infinity booster set, then in the Dark Revelation Volume 4 booster set and finally released in the Collector Tin Series Promos:
 * Uria, Lord of Searing Flames
 * Hamon, Lord of Striking Thunder
 * Raviel, Lord of Phantasms

These were the main plot of Season 1 of Yu-Gi-Oh! GX, and they are the legally "better" versions of the Egyptian God Cards.

While the Egyptian God cards have a fusion form named The Creator God of Light, Horakhty (Anime and Manga only), the Sacred Beasts have a combined form Armityle the Chaos Phantom, a fusion of the three, which has been referred to as "The Ultimate Sacred Beast".

In gameplay, the Sacred Beasts have similarities with the Egyptian God cards. First of all, to summon, the player must sacrifice three cards depending upon which monster the player plans to summon.

Design
The designs of the Sacred Beasts, Uria, Hamon and Raviel were overseen by Kenichi Hara. Each of them resembles one of the three Egyptian God Cards; Uria, Lord of Searing Flames finds a counterpart in Slifer the Sky Dragon, Hamon, Lord of Striking Thunder in The Winged Dragon of Ra, and Raviel, Lord of Phantasms in Obelisk the Tormentor. Unlike the God Cards, however, they possess certain visual cues that make them distinct from their predecessors, including translucent wings and more pronounced claws and skeletal features.

The three Sacred Beasts are named after angels in Judeo-Christianity. Uria's name is an alternate spelling of the name of Uriah. Hamon's name originates from the Book of Esther (Hamon is considered an alternate spelling of Haman), and Raviel's name is an alternate spelling of the name of Raziel. Armityle, the fusion of all three Sacred Beasts, is named after Amitiel, an angel of truth in Judeo-Christianity, who some consider to be an archangel.

Anime History
In Yu-Gi-Oh! GX, the Sacred Beasts are legendary creatures whose cards were sealed by Kagemaru underneath Duel Academy behind the Spirit Gate, which requires seven Spirit Keys to open, as he could not unlock their power at the time. Should they ever be set free from their stronghold, chaos and darkness will envelop the world, destroying everything.

The Shadow Riders sought to acquire the Spirit Keys and revive the Sacred Beasts. In order to open the gate, a strong dueling presence is required; if the keys are stolen and placed in the gate, (as attempted by Don Zaloog (character)) for example, nothing will occur. To meet the challenge of the Shadow Riders, seven of Duel Academy's finest duelists were selected, these duelists were Jaden Yuki, Zane Truesdale, Chazz Princeton, Alexis Rhodes, Bastion Misawa, Lyman Banner and Vellian Crowler, and although the Shadow Riders were defeated, Kagemaru managed to awaken the Sacred Beasts because of the dueling energy released from the duels. In exchange for freeing them from imprisonment, the Sacred Beasts slowly returned Kagemaru to a youthful state, empowering him with the energy sapped from Duel Monster spirits, but Jaden Yuki's interference resulted in the man's downfall. They were thus locked away once more.

After Duel Academy is transported to an alternate dimension in the third season, a Yubel-possessed Marcel retrieves the Sacred Beasts and adds them to his deck, which boosts the summoning speed of the Sacred Beasts and also supports the summoning of their combined form, Armityle the Chaos Phantom.

When Jesse Anderson was possessed by Yubel he reappears after having been missing for episode 131 to 147, he uses them in a Deck based around quickly summoning the Beasts and Armityle.

Although Yubel didn't use them in her final Duel with Jaden, they were in her deck. What happened to them after Yubel merged with Jaden is currently unknown, although it is safe to assume Jaden returned them to their resting place. Alternatively, Marcel may have kept them, as their support card "Dimension Fusion Destruction," is stated to be his favorite card.