Citadel one death is a brutal game mechanic

After pathing for an hour to get to the isolated Iron Citadel (no others anywhere near by) I blurred through the map, no issue with mob density or rare difficulty. One phased the first phase of the fight in seconds, then got one shot by a Wolf mechanic I haven't seen in 600 hours playing (an ice shotgun spit type attack). I don't even mind so much, as I may have been playing a little cocky after how easy the map was before the fight. But now that citadel is gone? I can't try it again? 3-5 divines worth of drops, an hour of pathing, gone because I'm only allowed one death? Used up by a one shot boss mechanic? It just feels really bad. Frustration with a game is expected, especially when there is user error involved. But feeling bad because you've lost so much loot and time spent (wasted) isn't a good way to build your end game. Please fix.