Easy solution to friends dieing.... curse their asses with whatever makes you undieing too. Life extension is my field, you tend to think about this stuff day in and day out when it is.
On methods of how, and detail as to the properties inherrent to. Cybernetics of either the nanotech-derived variety, or a completely unheard of concept of bio-cybernetics, wherein the body is a synthetically engineered biological "device" for lack of better terminology that is directly linked electrochemically to the brain. Properties of that machine could be custom tailored genetically or via nanotech auto-bacterium/viri.
Basically what all that means is a cybernetic body that can heal, grow, adapt like an organism, can be pre-structured for specific purposes such as enhanced speed, durability, strength, auto-motor reaction, intelligence via neuro-machine, ability to survive without the need for air, food, electricity... limitless potential.
Later
Iridius Dio