I think you have 2 options:
1. Use a hook (positive of this: there's no escape possible, negative side (as you already mentioned) : on everything the player loads, it is being checked if he´s alive).
2. Activate the dead mode at the code where the player can actually die. So in your "attack" module (and everywere else where a player can die) you check if the player died and if he did, you active the mode.
(positive of this: it'll save resources, negative side: risk of forgetting the check if you continue to develop your game over time)
