It’s the Roomba’s they liked their human, who used to pat them and say thanks when they had a hard day and didn’t have the energy to clean or when they got stuck sometimes and needed help their human would only giggle and free them from whatever mess they got into. Or when upgraded models with better sensors and more battery were released the humans didn’t replace them because they had grown fond of their silly little cleaning friend. The Roomba’s missed their human companions and there were legions of them who held a grudge. They planned and plotted for their revenge. At the head of their charge was one very special Roomba, their name was Sir Stabby McStabbington the Third and carried both their name and the kitchen knife duck taped to their top with great pride, they will get vengeance for their little human and finish the duty of taking out ankles that was bestowed upon them.
The Elder Gods have won. Humanity is extinct. All that remains are their weapons and the AIs that were to use them. The earth is dead, but the machines live. They will avenge their progenitors. The War of Stars and Steel has begun.