And this, this, is a particular wound that none of them save Diego would ever have dared prod at — because none of them ever knew, none except for Allison, none were ever supposed to know but the Chalice had ripped that privacy wide open and bared it to view. Luther had forgotten, almost. He'd thought it was a fake Diego at the time, and even after finding out the truth afterwards, it had been easy to avoid drawing a line from point A to point B to realising that Diego had been privy to his absolute worst regret and seeing the nail in Luther's thirteen-year-long coffin, the one that Luther had hammered into place himself.

And of course Diego had weaponised it. Like going for the jugular.

And Luther's temper, that ever-constant guarded thing, flares like it only can with this particular brother. "Don't you dare," he grinds out, although Diego already has, and would, and will. "Don't you dare, Diego. You don't know how much I wanted to. You don't know what that cost me, holding down the fort after everybody else abandoned their duty—"