Uladians

"The Uladians are a species that appear to be completely artificial in nature. However, that isn't the case. Due to a widespread plague of some sort that rendered their males infertile and their females barren, the clock on the continued survival of their species began ticking. Focusing all of their resources and efforts to preserving their people, they developed technology that allowed them to move their biological consciousnesses into artificial bodies ('Frames'). However, this didn't result in actual immortality as one might expect. They soon learned that an individual's biological consciousness would still deteriorate over time, necessitating the use of 'artificial assists,' to keep the consciousness 'alive.' Unfortunately, one the ratio between artificial assists and biological consciousness tips too far towards artificial, then the consciousness must be terminated (actual death), as that person would simply become an artificial mimic -- rogue and unpredictable as the 'new' artificial being is unable to make sense of itself without the biological consciousness to anchor it."