Beelzeus of the Diabolic Dragons

Beelze of the Diabolic Dragons and it's evolved form Beelzeus of the Diabolic Dragons are Duel Monsters from the manga series, Yu-Gi-Oh! Their invincibility against both monsters and effects as well as their ability to match and disable their opponent's power makes them very difficult to defeat.

Beelze of the Diabolic Dragons

 * Cannot be destroyed by battle or by card effects. *When you take damage from an attack involving this card, or from an opponent's card effect: This card gains ATK equal to the damage you took.
 * This ATK increase is permanent so long as Beelze stays on the field.
 * This ATK boost is applied both if Beelze attacks or is attacked.
 * 3000 ATK / DEF
 * Level 8 / Dark / Dragon / Synchro / Effect
 * One of the Duel Dragons
 * Signature card of Sect Ijuin

Beelzeus of the Diabolic Dragons

 * Upgraded form of Beelze
 * Cannot be destroyed by battle or card effects.
 * Once per turn: You can target 1 monster your opponent controls
 * Any battle damage your opponent takes from attacks involving this card this turn is halved
 * Change that monster's ATK to 0
 * Gain LP equal to its original ATK.
 * 4000 ATK / DEF
 * Level 10 Dark / Dragon / Synchro / Effect

Faults

 * Beelzeus cannot stop battle-damage: meaning it will lose a duel if it takes too much damage. (It can prevent this however by being in defense mode).
 * Both forms have no defenses against unorthodox effects that don't technically destroy it. (Can still be tributed, returned to the Extra Deck, removed from play or discarded from the Extra Deck.)
 * Can be destroyed by Duel Winners.
 * Skill Drain (and similar cards) can negate these effects and make Beelzeus mortal.
 * The Wicked Avatar and Zushin the Sleeping Giant will always overpower Beelze via their effects and they are unaffected by Beelzeus' ability to reduce their attack (since they have no original ATK anyways).
 * Other monsters you control cannot attack while Beelzeus is face-up on the field.
 * Beelze requires the Synchro Summon of 1 DARK Tuner + 1 or more non-Tuner monsters that total 8 levels. / Beelzeus requires 1 DARK Tuner + 2 or more non-Tuner monsters.
 * This card is so evil and powerful that it corrupts its owner.