Griffin Grey was first introduced by Danny Bilson and Paul DeMeo in Flash: The Fastest Man Alive #1 (August, 2006). Grey was the roommate of Bart Allen, the Flash, Wally West’s successor and Barry Allen’s grandson from the future. They both worked at Keystone Motors. After an accident that left Griffin injured, his wounds healed and he discovered he had powers. Griffin became a costumed superhero named The Griffin. Grey soon learned of the cost of his powers. He began to age after each use. He kidnapped Jay Garrick, the elderly Golden Age Flash, to fix the side effects. Griffin died after a successfully staged disaster and rescue, during his battle with the Flash, Bart Allen.
The closest character to Evelyn Sharp is Evelyn Crawford AKA Starling. She first appeared in Birds of Prey Vol. 3 #1 (November, 2011) by Duane Swierczynski and Jesús Saíz. She was introduced as a member of the Birds of Prey with a history with Black Canary. At one point she betrayed the team to Mr. Freeze. She was introduced at the beginning of the New 52. She is currently on the run from the other members of the Birds of Prey.
DC’s Legends of Tomorrow Season 1 Episode 13: Leviathan
In the Comics there have been two daughters of Vandal Savage mentioned. Scandal Savage debuted in Villains United #1 (July 2005) by Gail Simone and Dale Eaglesham. She was a member of the Secret Six. She was hard to kill and very proficient in multiple forms of combat. She was an agent of the Mockingbird who hunted down the rogue members of the Secret Six in the New 52. In the New 52, FBI agent Kassidy Sage/ Savage was investigating a series of murders. Her father was in prison for being a serial killer. The story is kind of like a Silence of the Lambs approach. She was created by James Robinson and Bernard Chang in DC Universe Presents #9 (July, 2012). In the comics, Vandal Savage does not have a daughter named Cassandra.
The Leviathan moniker was used by Legion of Super-Heroes member Colossal Boy AKA Gim Allon. This version of the character was from Mars (Earth colony) and a member of the Science Police. His powers were to grow to immense sizes. The robot on the show is wearing the symbol most associated with Ray Palmer, the Silver Age Atom.