oh oh lemme join!
cause cause i have an honest opinion about the end of the world....ever see the movie Titan A.E.?
if not i will put it into a basis for you....
An energetic race called the Drej blew Earth up then a guy called cale found the ship launched by his father in order to make a new earth Cale and his girlfriend,Akima and his father's comrade Korso.Work
together to launch the ships Earth making thing to absorb the drej's energy to make a new earth also blowing up the drej's ship/home.
Sooooooooo can i be a drej? i wont kill! i promise
just attack other races from around the world! plus you said its late in the 2050's around when the covanent arrived on earth so Master cheif was around then too so your theiory doesn't work for geeks like me!
but i will still play if i can be drej !