I will admit to the similarities between Existence and Null, since Existence's original sole purpose was to counter it, because I thought Nero was as annoying as fuck lol.

However, I don't see what Alysis did as crossing any lines. She's basically using her Origin to amplify that aspect in something else, something that I don't think would be terribly difficult. It doesn't make Robert's summons invincible, but it does make them harder to disrupt and destroy. I don't think Alysis needs to be an Archmage to pull that.

Warning against power creep is noted, though.