It is a 5/500 chance to roll the unique table. I was looking at a particular item on the table so technically my math is correct

just get the drop smh

if I were you I would keep going until zenyte shard then pick it up and instantly teleport out and never come back. Otherwise... what does this look like? A waste of time. But the chances of getting another zenyte right after one is realistically zero. You'll be wasting more time killing and not getting anything worthwhile.

The other drops don't make it worth the hassle in my opinion.