I’m imaging a normal Infinity: Battlescape gameplay; three fractions fighting with each other, where suddenly Raid Boss occurs out of nowhere. And when it happens everything changes. All three fractions have to face new opponent. Because he just destroys everything what is out there, they have to forget their fight for control over the solar system. They have to cooperate together to deal with greater danger.
Enemies becomes allies.
All three sides have to kill bloodthirsty space whale!
Once they’ve done it, everything goes back to normal game play.