House of Thanos

House of Thanos is the family of the mad-titan, Thanos

Thanos
Patriarch of the family. He kidnapped millions of girls and boys from their families and raised them to be his personal assassins. He had no care for any of his children, shown when he didn't care how much pain Nebula went through to become "Gamora's equal". Gamora was his favorite daughter, even after she betrayed him.

Nebula
Nebula is a Luphomoid and probably the last of her species like Gamora is. She adoptive daughter of Thanos and adoptive sister of Gamora and Korath the Pursuer. Nebula was jealous of her sister, Gamora, but in reality hated her because Gamora just stood by and did nothing when Thanos continuously tortured Nebula. Also, Nebula hated Gamora because she was always the favored daughter and because she lost mortal combat. However, twenty-six years of hating each other, the two sisters ended their rivalry, but Nebula still swore to kill Thanos to save millions of little girls from her fate.

Gamora
The adoptive daughter of Thanos and adoptive sister of Nebula and Korath the Pursuer and several other children. Gamora is a Zehoberei and also the last of her kind. She used to fight for her life to survive, and often bested Nebula in mortal combat. However, every time Gamora prevailed, Nebula's appendages were replaced with machinery so she cold be "her equal". Eventually, Gamora betrayed Thanos and stole an Infinity Stone, intending to save the Galaxy and get money to get far away from Thanos and Ronan as possible, but instead became a Guardian of the Galaxy and became attracted to her leader, Peter Quill, a half-Celestial, half-Human.

Nebula and Gamora ended their rivalry after twenty years of hating each other.

Nebula's and Gamora's adoptive siblings
Not much is known about these siblings, but it is known for a fact that Nebula hated them the most, meaning they had an unhealthy relationship with each other. Known relatives include Corvus Glaive, Cull Obsidian, Ebony Maw, and Proxima Midnight