Notes:

Context: there's this alien planet who had a prophecy that one guy from earth, Colossus, could destroy their home planet, so they send an army to earth to escape from this fate by killing the mutant and anything between their mission.

So Agent Brand forcibly recruited Colossus and friends to her mission. This not only diverts the attention of the army from earth but also with the powers of the X-Men they can stop any plans this aliens have about planet earth.

This scene is the briefing explaining who are these aliens and their prophecy, which Colossus makes this sarcastic joke.