(Chaos IV) Ultrastorm Leviathan

Lore
The Leviathan's massive frame was born fully formed. Any attack, no matter how strong, would simply be absorbed. It could only be defeated with a single blow of devastating might delivered in an instant.

Acquisition
Evolve (Chaos I) Ultrastorm Leviathan with Leviathan Catalyst three times.

Name origin
Leviathan is a creature with the form of a sea monster from Jewish belief, referenced several times in the Hebrew Bible.