I missed out on 4 to 5 charges when an orc I've killed a couple of times for decent charges before teleported from my vault and died to damage from the waves in the western aryth.

There are at least 3 completely different strategies to avoid dying to vault even after being slept by an ap. None are 100 percent effective but they are all very effective. They are all a little bit of a hassle though so sometimes you just stuck up the death instead.