Riva, alias Leva in the original Japanese iteration, operates as a deputy antagonist within King Mercenare’s Selfish faction. His clown-inspired appearance features bat wings flanking his ears, a razor-edged top hat, lilac-tinted hair, and yellow eyes accentuated by theatrical makeup—a visual nod to his Leviathan-derived name and embodiment of envy.

Paired with Gula, the gluttony-themed counterpart, Riva weaves strategic deception through playful taunts and calculated mind games, often favoring dramatic flair over pragmatic efficiency. This showmanship repeatedly sabotages his near-certain victories, exposing vulnerabilities during clashes. His signature weapon, the bladed top hat, spins as a lethal projectile capable of cleaving solid materials.

Following the initial Selfish trio’s defeat, Riva and Gula deploy a corruption-spreading tree to spawn Jikochuu monsters by exploiting human selfishness. The scheme nearly crushes the heroes until enhanced weaponry annihilates the spore-emitting tree. Forced into a merged Distain form upon defeat, the duo is purified but later drained of dark energy by the resentful Bel, culminating in their fatal disintegration.

Though Riva’s partnership with Gula begins as a pragmatic alliance, their rapport fractures into frantic discord as plans unravel. His tense dynamic with Bel escalates into mutual antagonism, triggering Bel’s betrayal. Despite orchestrating manipulative schemes—amplifying civilians’ negative emotions or psychologically destabilizing foes—Riva’s vanity and performative instincts persistently erode his tactical edge, cementing his role as a cunning yet self-sabotaging force within the narrative.