That said, I don't think "Erasing someone to the point they come back to the Monad" really constitutes Existence Erasure with Tier 0 hax potency, or anything like that, since all you're required to do is to wipe out the traits that individuate a person into something "separate" from the Monad. If a verse has souls returning to a 1-A void upon being erased from existence, I wouldn't say that means all soul destruction in that verse actually is 1-A Soulhax.
It is, however, Tier 0 BFR, functionally speaking. Which is to say: It isn't impossible (Or even particularly hard) to resist erasure of that sort, but if you don't resist it, then, yeah, you're completely cooked. No return for you.