Well there is another contender class A.I floating out there in the milky way. Offensive Bias. the un-rampant fiercely loyal to the forerunner the more cold calculating mechanical of two. where as MB has somewhat develop beyond his original self past insanity become something of living breathing sentient being onto itself. OB has not had this kind of personal kinda just being itself in confines of space as not being part of the liberians plans which now dictate and confound the current situation(ur-didact) Speaking of which OB has an undying allegiance to forerunner and there seems to be a certain one who is practically insane himself with a severe case of the butthurts for humanity. who also happens to have is own personal army lead a by one of the savviest and intelligent of known sangheili Jul M'dama who uses the forerunner worship so ingrained in his former covenant soldiers as tool in his quest for power revenge against the human race. Also they have halsey. also what better way for MB to have the atonement he so desperately craves then to help the chief save humanity and the galaxy. all and all i like where the fiction is right now