So what is the relationship of God's sovereignty to the individual sinful act of the rapist?
Getting back to the OP: What is the relationship of God's sovereignty in the Paris terrorism to the sinful acts of the terrorists, organised by
Daesh, who committed the evil?
There is God's good purpose during any evil thing. But we need to pray and submit to Him so we discover His good which He intends. I might not be able to tell you what, for you personally, is God's good which He intends for you because of children being raped and terrorists sucker-shooting and sucker-bombing people.
But we see how people of Satan's kingdom can use things. There are abuse victims who themselves have become predators. I think this could be because all have been born in sin, and who are in Satan's kingdom, therefore. So, if an evil person does what is cruel to a child, this can give the child ideas of what to do to other people, later. And, instead of using ideas from how kind people have treated the child, he or she could go with evil, instead . . . because of being in Satan's kingdom. Yes, in an animal kingdom there are predators and prey animals; and likewise in Satan's kingdom there are victim and victimizer people. And victims can become victimizers.
In Satan's kingdom, people even can use good things as a reason for them to suffer . . . including how people even suffer because God is providing us with rain which is so needed for life on this planet and is such a marvelous wonder of God; but that spirit of evil even has people suffering about rain and criticizing it as being "bad". So, even if a child is not raped . . . still ones on selfishness can invent ways to get hurt and keep on suffering, even about good things . . . like Satan in Heaven was not satisfied . . . even with such perfect circumstances and all the loving that was there.
So, we need to see how we in Jesus are not victims or predators, but stronger and creative in God's love, so we even make good use out of horrible things . . . because we are creative, with God.
This is what Joseph did, even after his own brothers betrayed him and their father, by selling Joseph into slavery and fooling their own father into believing Joseph had been torn apart and eaten by a wild animal > Genesis 37-50. Joseph with the LORD used his situation to help many people, and he did this even in a family caring and sharing way, even with his own brothers once he had the power to control what happened to those brothers who had betrayed him > Genesis 50:19-21.
What I personally understand is that this earth is the temporary holding sewer for
"the spirit who now works in the sons of disobedience" (Ephesians 2:2), a prisoner-of-war-camp for Satan and his evil invisible beings and humans who live in his kingdom's evil spirit of selfishness. Because God in His overall control has evil organized so it does not just spread all around and mess up everything. Evil people and even victim sinners are vessels of the spirit of selfishness. And their wrong spirit is flowing on its way to the flaming sewer which burns with fire and brimstone.
Meanwhile, out of this world which is a gigantic sewage system and prison of sin, God is adopting children to become like Jesus (Romans 8:29, 2 Corinthians 5:17). And Jesus makes us strong so evil and things of day-to-day living can't get the better of us and break us down in nasty angry reacting and arguing and complaining and hurts and unforgiveness and lusts for pleasure. We in His love can be free from how evil would effect us > we can use anything for love purposes . . . even taking advantage of evil things while staying in family love, like Joseph did > Genesis 50:19-21.
So, for us, it is our Father's sovereign will how we use any and all things for getting more and more into His family caring and sharing relating with one another, while ministering for any evil person, at all, to become adopted . . . like Saul became our Apostle Paul. Be ready for how God is able to change any evil awful person to become adopted.