Army of one.
If you are a thelasian citizen of at least 21 years you can apply to the Immortal program. Once deemed worthy and aged to 50 years (or mortaly wounded) you can become an Immortal. An Immortal is a new person by law, with a fully robotic, androgynous body (Frame) but with a human mind nested in the Core.
You will have the choice to either join the military or to take an oath and become a Creed Immortal, traveling the world and make it a better place.
With over 2,2 meter in height, impressive artificial muscles and a skin that can withstand all but the most powerful infantry weapons the Frame is a terrifying weapon in itself. No wonder that you are given a trimmed down version at the start. Even with half a year of training small mistakes can lead to lasting consequences.
In public you will see Immortals mostly hidden behind their iconic cloak to avoid upsetting civilians and to also make people stop staring at your very very naked body (it is a thing).
Once proven capable an Immortal will eventually get access to more advanced Frames, designed and specialized for various roles. Beyond this every Frame has a certain amount of untapped capability which allows the addition of Modules and with it customization.
Additional electronic packages can offer better sensors, improved shooting and drone control. Frame and Add-On Modules provide protection or damage reduction against specific damage types or completely new capabilities like a grappler or a personal stealth cloak.
To top things off Immortals have access to high grade equipment and special massive weapons fitting their physique. A “simple” massive pistol for an Immortal can match the penetration levels of most semi-automatic rifles on the open market.
A high tier Frame is one of the most deadly things in Celtara. With physical capabilities vastly outmatching humans even with the best implants and the ability to endure immense damage nobody can ignore even one of them.
If you want to learn more about Immortals, look them up in the Core Rules.