Theodore-A399

"No. Redboard."

- Taser in his usual speech.

SPARTAN-III Alpha Three-Nine-Nine, nicknamed Taser-A399, was a washout of SPARTAN-III Alpha Company, and remained with the program on Onyx as a drill instructor for Beta and Gamma Companies. Born Theodore Adan Serrano on March 12, 2522, he lost his parents at the age of eight when they were murdered in the Battle of Eridanus II, and after living in foster care for a year was recruited by for the first of a new generation of SPARTANs. While he passed the first tests, he would wash out after losing both of his arms in an accident which killed another trainee. When flash cloning proved inviable, he would be forced to wait for the development of high-grade prosthetics, by which time Alpha Company had graduated.

Though bitter over the event, he agreed to help train future generations alongside other washout drill instructors. Often spiteful towards the new candidates, Taser made for a vicious instructor, and was twice confined to quarters over incidents. After Beta Company graduated, though, he befriended Aspen-B145, one of their washouts trained as a medic, and worked together for training the Gammas. Kurt Ambrose continued to try finding a way to graduate them as full-fledged SPARTANs, and with help from Aspen and Deep Winter, finally succeeded. Most or all of the former washouts were brought with Gamma Company aboard the and completely or partially augmented, and given an accelerated recovery schedule. Following this period of readjustment, Taser and Aspen were requested for a special project in the UNSC’s development centers in Japan. Accepting despite its non-combat nature, they immediately began work on Project: HIPPOCRATES together.

The project's success came in the nick of time, with the Covenant's assault on Earth coming just as they had a working prototype. While the MJOLNIR Mark V(b) suit they'd modified went to Aspen, Taser received his own suit that he quickly went to work tinkering with. Taking on a number of high-risk missions, the pair became cornered at a fire support base by Brute Stalkers, and were forced to hold out until the arrival of Ion Team. Joining the three Gammas led by Kodiak-G114, they took part in the Battle of Nanto before learning of an assault on Ryu Base, and immediately went to their aid. The SPARTANs split up, and Taser led a marine team to secure the roof, only to find the Jiralhanae Chieftain Attilus with the base's captured command staff. Against orders, Taser engaged the Chieftain and his guard in brutal combat until only the two of them remained. Kodiak had just reached them when Attilus gained the upper hand, and ran him through, leaving him to bleed out as he engaged the new SPARTAN. Both survived the encounter, and Kodiak recovered Taser's body and equipment.

Personality and Traits
"Negative, time is zero. Terminating."

- Taser's last communication.

Spending more time studying computer code than interacting with other human beings, Taser adopted a form of half-code digitalk which most found irritating. Despite his anger, he had exceptional patience for working with computers and delicate hardware, and when calm was an excellent problem-solver. Aspen was probably his sole friend after his accident, the rest either dead or driven off by Taser himself. Even Lieutenant Commander Ambrose was known to call him by his nickname. After being held back for so long, he relished the opportunity to prove himself in combat against the Covenant, though his haste and overconfidence in his abilities cost him his life.