In Neon Genesis Evangelion the Second and Third "Impact" events are cataclysms caused by the union of human and "angelic" beings.
The Second Impact resulted in an explosion with the equivalent power of 18 billion megatons of TNT. Two billion people died immediately from tsunamis, while subsequent wars brought the total death toll to half of the earth's population.
In Rebuild of Evangelion 2.0 (a remake of sorts) a "Near-Third Impact" event occurs. This is extremely destructive, defying gravity, and tearing the natural and built environment apart physically. This event is cancelled through the Spear of Longinus before it can result in further destruction.
In the original conclusion to the saga, the End of Evangelion movie, a full Third Impact occurs. In addition to physical destruction, the barriers between human bodies and their souls are broken down, as well as the barriers between all humans, resulting in a union of all of humanity.
These impact events were all caused by human initiative. One faction, Seele, desired to cause these events so that humanity would be united as one soul in one god-like angelic body, a scheme called Instrumentality. An opposing faction led by Gendo Ikari opposed Seele, but he still desired the union of the human and the angelic, as he believed it would allow him to be reunited to his wife. It is not exactly clear what his plan is, but fans theorise that he intended to allow the Third Impact to occur as well as Instrumentality under the belief that he would then be able to reverse it. If the Angels had initiated the Impact event then it would have resulted in the complete destruction of humanity.
These factions were prepared to initiate the Third Impact earlier than they original planned in order to have control over it, and to prevent the others from doing so, so I think these Impact events can be considered deterrents of a sort.