Forerunner-Sontaran War

Forerunner-Sontaran War refers to a hypothetical scenario which, should it ever come about, would cause a paradox to occur and bring about the end of the universe.

A clash of failures on a monumental scale. The paradox would stem from the fact that both races are pathetic fighters and neither race can win anything, leading to both races losing. Since one has to win in order for time and space to remain intact, the paradox appears.

Thankfully, this will never happen as the Forerunners are completely extinct and the Sontarans are still going around failing as usual. Phew...