The Synod of Worlds is a Universe spanning governmental beauracracy and has departments setup to regulate every conceivable sentient activity. When worlds are deemed unfit to be chosen for inclusion to the Synod they a marked for extermination. The Department for the Extermination of Anti-Synod Terrestrial Habitats was formed to carry out the global genocide of these doomed worlds. The D.E.A.T.H teams use convicts and the terminally ill to harvest intelligences for implantation into cyborg bodies and given extensive combat training, hypno-indoctrination, and extensive implanted memories of all known hostile worlds and their know capabilities and armaments.
Most are implanted into tactical combat bodies roughly the size of your average sentient being. These have been code named "Immortals" by the Terran Aaliance since it has been confirmed that an un damaged "brain box" can be salvaged and re-used in another cyborg body.
Some of the more talented or experienced operatives are implanted into larger, stronger, tougher and more heavily armed bodies to support the line troops. These mid sized cyborgs generally lend fire support to the "immortals" and carry heavier armor and weapons. They have been code named "Jotuns" after the old Norse Ice Giants since a Jotuns is about 12 feet tall.
The large cyborg are split into two different but similar types. The smaller once is called an "Yami" while the larger and most heavily armed and armored of the cyborgs has been called a "Yama" after the Hindu twins who govern the underworld.
Typically the Synod will use these D.E.A.T.H. Squads as commandos and perform missions to remove ancient terraforming and control devices from a Fallen world before the main fleet arrives with a World Eater machine to end the planet's existence. The cyborg soldiers have also been used to terrorize borderline populations by kidnapping or killing their leaders or infiltrating before an invasion to knock out key defensive positions or command and control nodes. They cyborg soldiers are very well trained and experts in all of the combat arts.
Here are the Immortals and Yami/Yama cyborgs. I haven't painted up the Jotuns yet but I just primed them this morning so I should have them finished tonight.
The Immortals are Shalur mercenaries from Rebel Minis and the Yami/Yama class are Star Wars minis from WoTC and I believe they are Dark Trooper models.