To be fair, it's not like Suiboku is famous in this day and age. If you heard about someone making artifacts and elixirs, your assumption would probably be 'alchemist' or 'magical engineer', not 'ancient, vengeful demigod'.
This bothers me a bit, because it feels like a "win the fight but lose in a cutscene" situations. Realistically, Anise should have won, but because the script called for her to lose, the had to make up an oddball reason for it. This just doesn't feel like a believable outcome.