Some of the quipping about decentralizing D&D in the riffing on old games reminded me of Armored Troopers VOTOMS and the rpg that R. Talsorian Games published based on it. So you can tanking Jared and DanS for this partially. It's mostly done. Just need to figure out how I want to handle the programming of VOTOMS that is thing in the anime.
Traumatized Mechanized Infantry Soldier
You were betrayed by your unit deep in the humpbacked sky on a raiding mission. Left to suffer a slow death in the void through a combination of luck and a seemingly bottomless well of resolve found yourself on the outskirts of <insert your choice of multiplanar megalopolis with a junkyard>.
Light environmental suit
Partially refurbished solo standing tank
3 Standing Tank Fighting
2 Fist Fighting
2 Micro-grav Fighting
2 Standing Tank Programming
2 Pistolet Fighting
Whenever you are reduced to zero or less Stamina, test Luck to survive, adding an advancement check every advanced skill you possess and add point to your maximum Stamina and Skill. (Note: this can clearly be abused so like don't or you might just die anyways).
You may test Standing Tank Programming <something involving initiative or as dodging skill?> as well as to have your Standing Tank act on its own for a number of rounds equal your to Standing Tank Programming skill.