Here’s my interpretation.
A status that has been removed can’t effect you on the basis that you don’t have it anymore. Thus soulbound must kill you BEFORE it’s removal.
Therefore when you enter purity with soul bound the order of operations is:
- Purity initiates the status effect removal proccess
- Soulbound realizes that it’s about to be removed and kills the player
- Soulbound is removed
- Purity completes the status effect removal process
Thus if you are healthy or the saint then you will tank the death during step 2 of this process with the status effect being removed in step 3.