[-] Lukasmah suggested:
Since you respawn at a random point in time, keep killing yourself until you're close to the time the box opens.
You would absolutely do that right this instant, if you were not cursed to respawn in the sameish time and place as your death, forever binding you to this period until you lift the curse from both you and big H by killing him or being killed by him.
You make the executive decision to postpone the suicide spree until it would actually be useful.