The phoenix that fights itself, then rises from its ashes stronger than ever. That is the Crucible.
What's the Crucible? Before the days of the City and the Iron Lords, it was a place to pursue vendettas. To battle for territory, and pettier reasons. The whole world was a Crucible arena. The Crucible today? To Cayde-6, it's a gambler's paradise. To Zavala, it's a resource sink where equipment goes to die. To Ikora, it's home—though she would never admit it.
Partial answers. The tactics and techniques that will save us in wars to come are birthed in the Crucible, during live-fire training. The Vanguard are so preoccupied with their own agendas they're missing the Vanguard of tomorrow rising right before their eyes.
Ghosts find Guardians. The Crucible forges them.
– Lord Shaxx