Uncho's Iai is one of Johnny's Overdrive Attacks, only appearing in Guilty Gear XX Λ Core Plus R.
Overview[]
Johnny slashes his opponent diagonally downwards, akin to Killer Joker. As the opponent gets launched, Johnny lands feet-first on the ground with his sword still out, then re-sheathes it just as the opponent is about to hit the ground, striking a pose as the screen whites out, showing the silhouettes of both characters.
EX Johnny's version has the opponent get launched higher - so much so that Johnny takes time to prepare to tip his hat and have his sword almost fully sheathed. As the opponent lands, Johnny lowers his head. The screen does not white out for this version.
Details[]
Uncho's Iai is an overdrive made for one main intended purpose: To cover Johnny's lack of oncoming midair anti-air counters against characters with special "shoryuken" anti-air or midair special moves with long trajectories and fast speeds that can bypass Ensenga and Mist Finer. The threat of this overdrive allows Johnny to punish rushdown tactics and forces the opponent to respect Johnny's aerial lead ins, forcing them to play to his rhythm and to think twice about leading in recklessly.
EX Uncho's Iai's long delayed reaction time is actually a benefit to EX Johnny's fighting style. The nature of this delayed reaction is meant to taunt the opponent, to unnerve them and make them more aggressive to allow the player to lash back with EX Mist Finer's counterstances, and if Johnny is in the lead, deliberately wastes time on the clock and puts Johnny at the lead healthwise to place pressure on the opponent for further provocation and knocking them off their competitive edge.
As an Overdrive Move, once used, the player best be prepared as a good Johnny player to back their style with substance. The damage of Uncho's Iai is small compared to That's My Name, and makes the attack more of a provocative gesture unless it is used to guarantee victory.