A serial killer from [[Fate/Zero]]. 
Though he is not a magus, he was selected by the Holy Grail to fulfill the war's requirement of seven Masters and seven Servants. 
Ryuunosuke knows nothing about magic or the fourth Holy Grail War; his involvement in the war is simply to watch [[gilles de rais (caster) (fate)|Caster]] kill people in unique and thrilling ways.

h4. See also

* [[Gilles de rais (caster) (fate)|]]
* Type-Moon wiki (spoilers): http://typemoon.wikia.com/wiki/Uryuu_Ryuunosuke
雨生龍之介