iskander flick

"That's what mattered, fool."

Along with his shocked voice, something burst in the middle of Waver's eyebrows. The completely unexpected pain and the surprise make Waver fall off then tumble flat on his face.

That was Rider's middle finger. Holding it bent by the thumb then shot forward: that's a flick on the forehead. Of course, there was no strength in that. However, when it's Rider's finger, hard as the root of a pine tree, Waver's skin swelled red from the force.

- Fate/Zero: Act 2, Part 4