Aboru

is character who made debut in The Seven Deadly Sins: Grand Cross mobile game, but later appeared in the official Manga.

History
Jericho and Howzer were sent on a mission to deal with a Demon of whom Bartra had a vision about. Aboru introduces himself to them as Galand's nephew. After discovering his uncle was killed by Escanor, he began to attack them. However, Aboru is presumably defeated by them.

Galand
Not much is known about their relationship. However, Aboru was furious when Jericho and Howzer said he was killed by Escanor, implying he really cared about his uncle.

Trivia

 * It's unknown what family relation Aboru and Pump have.