"Blood is taking in someone who has no home and making him forget each and every day that he actually wasn't born into your family. Blood is tending to scratches and bruises. Blood in constantly being an annoying nag and worrywart. Blood is more than mere hemoglobin, more than just DNA strains held in this red liquid." He moved closer to Lois, eyes narrowing further. "Blood is family, blood is claiming, blood is owning, blood is life and blood is... blood is..." He suddenly slammed his palm on the shield, splattering blood all over it. "She's my blood. Not them." Lucas to Lois, Chapter 93: Steppenwolf
Lucas Dunleavy is the bastard son of Lionel Luthor, who was raised in an orphanage as an experiment of his father's to see how a son of his would group up with privilege. John Balcoin interfered in this experiment when he took Lucas in so he could not only have a Luthor groomed to be faithful to him, but who would also keep his son Mikhail entertained and thus out of John's way.
Lucas was a part of the Lost Boys, but joined Chloe's Balcoin Circle, replacing Whitney Forman as her Hand. Lucas expressed confliction over this as he wanted to be a part of Chloe's Circle, yet feels he's gone over Mikhail's head by being chosen first.Lucas has yet to fully understand the role of Hand, except that it is the counterpart of the Darkseid Thunderbird, a warrior and protector.
Having grown up knowing that he'd been discarded by his father, Lucas has grown to resent his birth family. His loyalty to the Balcoin family stems not only because he was raised by John Balcoin, but because Mikhail Balcoin is his best friend.
John was not much of a fatherly figure, and while he technically" raised the Lost Boys they grew up without any sort of emotional support. As such, Lucas is both uncomfortable and unnerved by Chloe's brand of parenting - although he grows to enjoy and expect it, going as far as to call her "Ma", despite how many times she tells him not to do it.
Lucas is tough as nails and not above killing or torture to get his ends.
Lucas has not shown himself to possess the special Luthor life-taking ability like his oldest brother, Lex, but he is a very strong and capable fighter - both magically or physically.
He is also learning what it means to be the Balcoin Hand, and whatever ability might come from it.
Mikhail and Lucas grew up together and became closer than brothers. They have an extremely close bond and will do anything for each other. After finding out that Chloe was the Firstborn they both conspired to become a part of her Circle, and yet Lucas felt like he had betrayed Mikhail by being chosen before him. Mikhail, though resentful and insecure about it, pushed his own feelings aside to cheer and encourage Lucas.
While he at first flirted quite aggressively with her, Lucas quickly realized that theirs wasn't a romantic relationship. In fact, she somewhat scared him. He quickly grew to respect her, and while uncomfortable in the beginning with her mothering nature, eased into the role of spoilt kid. Through Chloe, Lucas has found a family and somewhere to belong, and chose her over his birth family when presented the opportunity.
In the beginning Lucas just wanted to kill Cassie due to her part in killing John, but he and Mikhail both decided not to because they knew it would mean they'd never have a place in Chloe's Circle. Lucas has grown to tolerate Cassie, and has even agreed to work with her to better protect Chloe from not only present dangers, but future as well.
Lucas hated Diana Balcoin due to her role in John's death, but accepted that he wouldn't be able to take vengeance on her actions. Diana and Cassie are still not his favorite people, but he tolerates them both nonetheless.