Creation

Pioneer first appeared in Marvel Zombies Supreme #2 by Frank Marraffino and Fernando Blanco

Major Story Arcs

The Harvesters

Pioneer was seemingly the lone survivor of The Harvester's encounter with a zombified Hyperion, though by no fault of her own. Just as Hyperion was about to eat her, he died (again) from Mad Cow Disease he had obtained from eating tainted cows minutes before.

Pioneer was able to divine this information from the smell of the cattle and the smell of Hyperion. She was successful in calling upon the "Power of the Prairie" and raising the previously eaten cattle from the dead to trample Hyperion momentarily.

The Paladins

After the Initiative folded, a few recruits, including Pioneer, from across the country came together to form The Paladins, believing they could do a better job without government supervision. The Paladins were desperate to make a name for themselves, so they worked with Veronica Eden, who dreamed of leading Hydra, to fake superhero battles. When Eden was arrested, The Paladins decided to activate The Overseer from Eden's storage to replace her but were easily overwhelmed.

Fifty-One was the only one regretting abandoning Overseer to its own devices. He wanted to warn someone, but Think Tank psychically controlled him. To protect themselves, The Paladins turned Fifty-One into the villain they could publicly fight.

When Fifty-One broke free of the telepathic control, he broke Eden out of prison, getting the attention of Iron Man and Captain America. They believed the story The Paladins told about Fifty-One going rogue, so they returned Fifty-One to their custody after catching him. The Paladins almost killed him when Cap and Stark learned the truth and came to Fifty-One's rescue.