Demon’s Souls had already embraced the opaque design and challenges of classic games, adding names like Ornstein and Smough to the wince-inducing canon of legendary video-game big bads. Then a wave of nostalgia brought the boss back. Open-world and online games flourished, player choice became paramount, and boss fights in games that felt otherwise wide open - like the notoriously underwhelming boss confrontations in otherwise acclaimed games such as Bioshock or Deus Ex: Human Revolution - ended up feeling like dead weight. Bosses were effectively bottlenecks at a time where games were expanding. Until somewhat recently, it seemed as if the concept of the video-game boss was on its last legs. It’s both Destiny 2’s biggest challenge and mystery, and for the past week the game’s community of players has been racing to square off with Leviathan’s mysterious boss, six people at a time. That’s the name of the game’s marquee Raid, a massive, sprawling level that explains almost nothing about how to beat it, and requires teamwork among six players to solve its riddles and take down whatever boss lies at the end. Last week, Destiny 2, a highly anticipated online shooter that’s best played with friends, raised the curtain on a mystery it had been teasing for weeks leading up to the game’s early September release: the Leviathan.