Personal Info:
Real Name: Unknown
Also Known As: No known Alias
Place Of Birth: Unknown
First Appearance: Alpha Flight Vol.5 #38 (1997) Modern Age Villain
Known Associates: No known Associates
Group Affiliation: None
Base Of Operations: Mobile
Grudges: Aquaman
Creators: Peter David and Jim Calafiore
Possession: Rhombus being is contained in a gem, which is able to possess the body of anyone who touches it.
Amphibious Physiology: Rhombus can not only survive underwater but he can also survive on land. He can extract oxygen from water and his physiology also allows him to withstand extreme changes in water temperature typical of great ocean depths.
Energy Manipulation: Rhombus can project powerful energy blasts from his hands.
Flight: Rhombus is able to fly.
Rhombus is a being that took human form and seduced Tsunami (Miya Shimada) and by his own account, he believed that he and Miya conceived her daughter, Debbie (Deep Blue). After Debbie's birth, Rhombus revealed its/his sinister side and attacked Tsunami. Miya defeated him with the aid of the ancient Atlantean sorcerer, Atlan (father of Aquaman and Ocean Master). Atlan stripped the gem from its host and banished it to space. Years later the gem returned from space, striking and killing an unemployed man. The gem later reanimated the corpse and Rhombus was reborn.
Rhombus at Aquaman Wiki
Rhombus at Comic Vine