Story:

The Deacon was deployed for only a limited time as a proof-of-concept machine. Only four units were constructed, and each was entrusted to a member of the Newtype Corps' Geist team. Composed of Space War veterans from varying backgrounds, these older, experienced pilots used their mobile suits against members of the Ark Orion Defence Force, initially with great success. In addition to the added durability of their Divinium armor, the Deacons elevated the namesake Newtype abilities of each Geist dramatically. In the case of team leader Darbin Styles, for instance, the Proto Resonance increased the mental bond of his natural mind-machine linking abilities, giving him elevated reaction time that surpassed that of most human beings. Likewise, psychological warfare specialist Dr. Wilfred Kain was able to distract most of the Defence Force with incredibly vivid mental projections of their worst nightmares.

Unfortunately, the Deacon's Proto Resonance proved far too powerful for the suit's common Neutron-S engine to manage. Geist sniper Jessica Hein-Styles found this out the hard way when her mental 'Siren's Song' abruptly collapsed, making her intended targets very much aware of her hidden position. Likewise, other members of the team found that, without their Deacons at full power, they were unable to cope with the tremendous mental feedback of the imperfect Resonance devices. As a result, the team was immobilized by its own equipment, and wiped out by Ark Orion's soldiers. Not long after these events, the Newtype Corps perfected the Cerberus-class engine, though it passed over the idea of constructing more Deacons in favour of the War Saint project.