The guy who injured Ely as a child was an early, unstable prototype of The Controller’s work -- natural abilities enhanced were all the Controller could do at the time. Once Erik and Tori were a part of it, his DNA was extracted to work on them, and when the experiments on them proved successful his usefulness ran out, and he was killed. The same happened with other people the Controller employed in the early days, and even some he uses now. For example, the vampiress he kidnapped to create Josh was left for dead once it was obvious there was little to no symbiotic connection between them, and it is entirely possible the same will happen to Luc if he is weakened too much from the experiments on him, and if the Controller gets what he wants from him.