Nadakhan is the prince of djinns, the captain of the Sky Pirates. He dominated seas, until faced Captain Soto. Soto trapped him in Teapot of Tyrahn while his crew was split up in the 16 Realms.
Centuries later after destruction of Djinjago Nadakhan was the last djinn. 
After he found out that his lover, Delara had died he reunited his crew he tried to rebuild Djinjago in the sky with parts of Ninjago. He then tried to marry Nya because she looked like Delara to get infinite wishes without rules.