The assassin was only serving the mastermind behind the scenes, and the mastermind, an elder from the Howard Family, was too old to withstand the punishment dealt by Alexander Summers. The elder passed away after enduring just a few blows, which is why Alexander vented his remaining anger on the assassin.
Purple was unwilling to murder, but if the other party was to suffer inhumane torment at the hands of Alexander, she would rather take their life herself.
This was not about being a saint or about kindness; it was a principle of conduct, a way of thinking formed by long-time teachings and the environment in which she was raised.
It was something etched into her bones, unchangeable.
In dealing with the world, between her and Alexander, there was a huge chasm.