“humanize the oppressor.”
I.e., humanize someone that they already went through the bother of dehumanizing. Murder is something that few people can do with a clear conscience. A non-human “oppressor”, though, they pretend that killing him is not murder at all.
To a Muslim, "oppression" is any resistance to Islam. Any who resist Islam oppresses the Muslim who wants to spread Islam. It is obligatory upon all Muslims to destroy those who resist Islam.