Again Jake, your perspective. I once left an abusive marriage and loathed to call myself a victim. I was unexperienced with abuse and wanted things to work out, but once I woke up to reality I took full responsibility for my part in the dance. I chose to make excuses and sweep the issues under the rug.
Until I no longer did, so you can quit with your hysterical accusations of “cruelty”, so-over-the-top melodramatic Jake.
I’ll add to the fact that the OP’s question sates his sister has recently gotten together with this person who is already showing his abusive colors in a short amount of time. In this case, if this girl/woman stays with this guy and makes excuses or ignores his behavior she is, absolutely, volunteering to be victimized. This is not a woman without resources, small children, financially dependent, or otherwise highly dependent on her abuser to meet her basic life needs.
I understand why women in those circumstances often stay, to their detriment, I wanted my family life to work out, but in a dating relationship you have all kinds of power to put an end to the situation in a heartbeat. Again, if you do not then you have crossed the line from being a victim to a volunteer. If one had a perfect stranger verbally or physically assault them they would file charges and take a pro-active stand against being accosted, that responsibility also applies in abusive relationships. The core issue in all abuse is that the neither the abuser or their victim takes personal responsibility.