>>717766738
Pay attention to the dialog there. Kreia asks you if you feel fulfilled and satisfied, having killed the masters. But every option you can choose is simply a variation of
>No. I must kill more.
This shows that the Exile, despite whatever intentions they had in killing the masters, has succumbed to the Dark Side, willingly. There is no catharsis or resolution, and just the same endless hunger as Nihilus that will consume everything until just a husk of the Exile remains.

The only way to be Dark Side and not trigger Kreia to believe you're a failure is to restrain yourself from killing the masters.