When Breaching Leviathan enters the battlefield, if you cast it from your hand, tap all nonblue creatures. Those creatures don’t untap during their controllers’ next untap steps.

Trample

Islandwalk (This creature can’t be blocked as long as defending player controls an Island.)

Shroud (This creature can’t be the target of spells or abilities.)

When Kederekt Leviathan enters the battlefield, return all other nonland permanents to their owners’ hands.

Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

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.)

Islandwalk (This creature can’t be blocked as long as defending player controls an Island.)

Islandwalk (This creature can’t be blocked as long as defending player controls an Island.)

All lands are Islands in addition to their other types.

Creatures without flying or islandwalk can’t attack.