Leviathan [The Dark] SV81 you can also Xyz Summon

you can also Xyz Summon "Divine Arsenal AA-ZEUS - Sky Thunder" by using 1 Xyz Monster you control as material

Set: Dragons of Legend 2 Card type: Fusion/Effect Monster Rarity: Secret Rare Attack: 2800 Defense: 1200 Must be Special Summoned with "The Fang of Critias"

As long as this card remains face-up on the field

it used to be seven men

Set: Zendikar Type: Enchantment Rarity: Rare Cost: {B} At the beginning of each end step

Leviathan [The Dark] SV81 you can also Xyz SummonSet: The Dark Type: Creature Leviathan Rarity: Rare Cost: {5}{U}{U}{U}{U} Trample Leviathan enters the battlefield tapped and doesn't untap during your untap step. At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap Leviathan. Leviathan can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)