Don't take it wrong but that's not evil plays.
That is nihilistic play.
IMO it's evil route of the story, but sadly only chaotic evil (at this moment). If you look up to my post close to the top, I wrote there a few examples of additional options which would provide us with additional choices representing most of alingments; especially neutral/lawful evil ones.
Lawful or Neutral evil character wouldn't kill Halsin for example, when siding with Minthara just because he is able to provide us with help. (Or at least player thinks that he can)
Same way of thinking goes why PC has a good reason to not kill Minthara (side of tieflings), simply because she knows quite a lot about the Absolute and PC could use this to a great exent.
