chidori or raiki

[SatchiZurake]

Kakashi just has better mastery of the technique, so his specifically earned the name Lightning Blade (or Raikiri, whichever you prefer). While it's true that Sasuke advanced Chidori in his own ways, with Chidori Spear, Chidori Nagashi, Chidori Senbon, etc, the base Chidori is just that--the base jutsu from which all of the above listed techniques came from.