Marcus, or Mark, was the second last Eternal to perish. Mark resented the choice he made to become an Eternal, and as such, he became suicidal. He did not attempt to fight when he was killed, but ran to them with open arms. Tux was Mark's guardian who preferred the shape of a black cat. Mark died in Santa Monica, California, USA, killed by the Gray Assassin, who used swords with hilts made of dragon teeth and magical blades. When he was hit, he turned to dust.
Source[]
- Keys to the Demon Prison (Fablehaven #5)