Major Story Arcs
Maggie and Brilla Session are the Session Twins, infamous dangerous (and expensive) adventurers and killers.
They are hired by the Grendel-Khan, Jupiter III, to find Grendel-Prime, the hero of a previous era who has been in hiding for generations. He hopes that Grendel-Prime will be able to prop up his weak leadership. Hearing of this, the rebellious Wyotek Jones hires the equally notorious Hitchcock Blue to find Grendel-Prime first.
The Sessions search for Grendel-Prime for over a year. They find out that he is working with Dr. Creach, and interrogate Creach's former assistant and lover, Joshua Radick. From him they find out that Creach and Prime are based in New York.
They finally find him and break into their base, where they see Grendel-Prime in a mysterious machine. They shoot the machine, causing it to malfunction, and sending Grendel-Prime into the past (where he confronts Batman in the second Batman/Grendel crossover). Since, they believe he was destroyed, however, they tell Jupiter III they will accept a reduced fee of only two billion dollars for their services.
Powers and Abilities
The Session Twins are famously skilled and dangerous warriors. They are known for their sadism. Maggie in particular calls herself the "mother of deception and pain" for her ability to detect lies.
Unlike her twin, Maggie has a robotic arm, which she can seemingly shape into a number of technological forms. She has been seen using it as a hand with long claws, a blowtorch, and a gun.
She also carries conventional weapons.