073 Alimony Bias

073 Alimony Bias was an Ancilla built by the Forerunners to oversee the maintenance of the Forerunner constructs. His duties involved keeping the Halo Array, Lesser Ark and Greater Ark, as well as the Shield Worlds, constantly in an operable state. He had command over approximately 60 million constructor sentinels all across the galaxy. 
073 Alimony Bias was eventually shut down before the war. This was due to the fact that Alimony Bias had been given a new schematic on improving a forerunner construct and when he inquired as to whether he could edit the plans slightly to make it more effective the forerunner engineers agreed. 
Alimony Bias continued with the plans but believed that many other installations could do with editing and improving. This desire ended up driving the Ancilla crazy and as such he began constantly editing all of the installations non stop trying to make it more and more effective and efficient. Alimony Bias would even order constructor sentinels to destroy homes in order to make improvements. In some cases he would cause deaths by forcing sentinels to build pieces of metal through living beings. 
The Forerunner's eventually decided to stop him and forcefully shut down a large majority of his sentinels. This made 073 Alimony Bias angry and he threatened to manually order his sentinels to activate a Halo Ring early. This forced the Forerunner's to shut 073 Alimony Bias down just one year before the array was fired.