Mag Agents are A.A.H.W. members who have been magnified to about two-and-a-half times their regular size. It was shown in Madness Combat 9: Aggregation that the Agent Magnification Chamber can not only magnify agents, but also resurrect dead bodies.

Why does MAG agent have spikes in his head?

1. He could've been impaled in the head with nails, then revived and turned into a Mag Agent. 2. He was an agent gone rogue and they killed him then put spikes through his head and magnified and revived him so he would forever feel the wrath of the AAHW.

Is Hank and Sanford dead?

Trivia. Sanford is one of three characters who have directly faced the Auditor in combat (along with Jesus and Mag Hank). Sanford appears to be the only protagonist not to have died in the canon series. It has never been seen how Sanford exactly obtained his hook.