Sydenn is a being created through sheer force of will by Nimraa during that being's time in exile following the death of Dark Earth.
Sydenn was created by JM DeMatteis and Yvel Guichet. He made his first appearance in Trinity of Sin #1.
Major Story Arcs
The Wages of Sin
Sydenn is sent by Nimraa to attack Pandora in Goa. As a rogue wave he sweeps over the beach she is on, killing dozens of innocent bystanders. He nearly drowns Pandora, but she is able to use her magic to transform herself and escape, briefly destroying him. He regroups with Nimraa's other servants and joins in the renewed assault on the Trinity of Sin. Later, he is present when the Trinity absorbs and destroys Dark Earth.
Powers and Abilities
Sydenn is a being composed entirely of sentient water. He is able to encase others inside his own body, drowning them.