Joshua is the emotional center the game returns to when everything else becomes too cosmic. The two brothers, separated by thirteen years of guilt and grief and misunderstanding, are now working toward the same end, and the promise that structures their relationship is simple: neither of them is allowed to die for the other again.

The game knows this promise will be tested. Everything in FFXVI that is personal eventually becomes structural — the loss of a brother is also the loss of a Phoenix, which is also the loss of a power that could stop Ultima, which is also the loss of a future that might have been possible. The promise never truly dies, but the weight of it keeps growing.