The Three Gods are the most powerful monsters in the entire game. So powerful, in fact, that they are forbidden from being used in the card game. However, that's not the only reason they can't be used in official tournaments. All three God Cards have effects but they aren't printed on the cards. In addition, the backs of each card are completely different. They don't possess the Konami or Yu-Gi-Oh! labels and they're differently colored. Fortunately, you can still use them if you're just dueling against friends.
The Three Gods were at one time the deadliest Duel Monsters ever. So powerful, in fact, that the pharaoh had to seal them up permanently. Many millennia later, Pegasus re-created these monsters in the form of cards. However, they were too powerful for even him to handle. As a result, he had Isis Ishtar seal them away. She took the cards from Pegasus and buried them in Egypt. Unfortunately, they were soon discovered by GHOULS, a group of elite duelists who seek only the most rare and valuable cards. Two of the God cards fell into the hands of the leader of GHOULS, Malik Ishtar. Isis was able to rescue one of the cards, which she gave to Kaiba. Later on, Yugi won one of the Gods from Malik in a Battle City duel. According to Isis, these three cards are the only monsters that are more powerful than Exodia.
How to use a God Card
1. You must sacrifice THREE monsters from the field to summon a God Card. This is considered a Special Summon rather than a Tribute Summon.
2. Any card effects may affect a God for only ONE turn, even if the effect is continuous. For example, if you bring back a God from the graveyard, it only stays on the field for one turn.
3. The only card effects that last on a God Card are ones that destroy them, such as Raigeki or Dark Hole.
The God of the Obelisk Attack: 4000 Introduction:The God of Obelisk, also known as the Lord of Destruction (Kaiba calls it that way) for its destructive power. It is capable of obliterating the entire enemy line, and defeating the opponent instantly once it attacks. It is the only God card that was avoided from being stolen when GHOULS raided Valley of Kings in Egypt. Isis Ishtar carried to Domino City and delivered it to Kaiba, hoping it would be a great way to lure out the other two God cards.
Card Text: The player shall sacrifice two bodies to God of Obelisk. The opponent shall be damaged, and the monsters on the field shall be destroyed.
English Card Text: The descent of this mighty creature shall be heralded by burning winds and twisted lands. And with the coming of this horror, those who draw breath shall know the true meaning of eternal slumber.
Explanation: So after you summon God of Obelisk, if you have two monsters left over, you can sacrifice those two monsters and activate the special effect, which will instantly destroy all monsters, and opponent will instantly take 4000 damage no matter what. However, Obelisk can't attack normally in the same turn its effect is activated. (No wonder it's called the Lord of Destruction. Too bad you can't use it in a tournament duel.)
Saint Dragon, God of Osiris Attack: X000 Introduction: Osiris is a monster capable of reaching near-limitless power when used with a specific combo. It was used by Strings, one of Malik's countless puppets. And through Strings, Malik dueled with Yugi in Battle City. Just as Yugi was about to get defeated, Yugi was able to set up an infinite loop of drawing cards, forcing Malik to lose due to deck depletion. Card Text: Whenever the opponent summons a monster into the field, it is dealt 2000 damage. X equals to the number of cards in its controller's hands.
English Card Text: The heavens twist and thunder roars, signaling the coming of this ancient creature, and the dawn of true power.
Card Explanation: So if you have six cards in your hand, Osiris becomes 6000/6000. As for the first ability, if a monster the opponent summoned has an attack or a defense of 1900 or less, it's destroyed instantly. If it's ATK is 2000 or more, it's simply lowered by 2000.
Sun Dragon, God of Ra
Attack: ???? Introduction: This is the only card that still remains stolen by Malik and GHOULS. Its powers are the strongest out of all three Gods. Its design is the strangest as well. When it is not in use during a duel, the card reads ???? Attack and ???? Defense. However, once it is used in a duel, it will emit a strange aura, and the aura will enable strange Ancient Egyptian Priesthood text to show up. There are a total of three special effects, which can only be activated when the verse is chanted out.
Card Text: Speed-charge, can attack the turn it is summon back into field by Raise Dead. English Card Text: Spirits sing of a powerful creature that rules over all that is mystic.
Card Explanation: In Duel Monster rules (in the anime only - does not apply to the card game) , you are not allowed to attack with the monster you just brought back from the grave. You have to wait a turn, but Ra bypasses this rule.
Surprisingly, Ra has more effects than the card mentions. Here are the effects along with their descriptions.
This Monster's attack and defense strengths are equal to the total respective attack and defense strengths of the Monsters sacrificed to summon it.
Those who can read and speak Hieratic can gain control of Ra.
Pay any amount of Life Points. Increase Ra's attack and defense strengths each by the number of Life Points you paid in this way.
Pay 1000 Life Points. Destroy 1 of your opponent's Monsters on the Field.
Like Toon Monsters and certain Special Summon Monsters (like Aqua Spirit & Dark Necrofear), the God Cards have several rules in order to be played legally in a Duel.
Dub Name: Obelisk the Tormentor
Owner: Seto Kaiba
Defense: 4000
Dub Name: Slifer the Sky Dragon
Owner: Yugi Moto (formerly owned by Malik Ishtar)
Defense: X000
Osiris has aided Yugi greatly especially during the duel with Yami Bakura when this was the sole card he relied upon.
Dub Name: Winged Dragon of Ra
Current Owner: Malik Ishtar
Defense: ????
First Verse: Whoever chants this verse, is the rightful controller of this monster. If the owner is unable to chant this verse, then this monster cannot be controlled.
Second Verse: When summoning this monster, if the owner chants this verse, then the owner shall sacrifice all life points until only one point remains. The sacrificed total shall be added onto Ra.
Third Verse: Chant the third verse. Ra shall transform into a fiery phoenix, and shall descend upon the opponent's monsters, incinerating all in its path.
Basically, the sum of the attack and defense stats of all the monsters you sacrifice is Ra's attack and defense power. For example, if you were to sacrifice three Blue-Eyes White Dragons to summon Ra, its attack would be 9000 and its defense would be 7500.
If you bring Ra back from the graveyard, however, its stats will be 0.
This was explained by Rishid during his duel with Joey in the Battle city finals.
Basically, whoever can read and speak the ancient Egyptian language of Hieratic will gain control of Ra, regardless of who summons it.
This ability was shown in Malik's battle with Mai during the Battle City finals. Mai successfully summoned Ra, but all that happened was that it appeared as a metal sphere, known as Ra's "Sphere Mode." When Mai looked down at the Ra card in her Duel Disk, its text had changed to Hieratic. Malik chanted Hieratic, which not only activated Ra, but gave control of it to him, as well.
Basically, you sacrifice as many Life Points as you like and the sacrifice LPs make up Ra's stats.
This was demonstrated during Malik's duel with Bakura.
Pretty self-explanatory.
This ability was revealed by Malik during his battle with Joey. He had used the ability to decimate Joey's soul. Joey survived for the moment, but the assault was too great, and fell prey to the Shadow Game, just as Mai had.