Acknowledging that you're WAY out of your league and should leave something to people with the ability to reasonably face a threat is also important.
That said, if slimes are worth 1p each (c2p23), just take a page out of certain person who's been grinding slimes for 300 years, rack up a ton of points on zero-threat monsters, and spend them all to one-shot the Unique. And then deal with the physical backlash, because, again, you're way out of your league here.