Shippu Jinraikyaku / Shinryuken
Ken's Final Smashes are named Shinryuken, a powerful uppercut, and Shippu Jinraikyaku, a rapid series of kicks. Which one is used depends on Ken's proximity to any given target.
If Ken is not close enough to any opponents, he uses the Shinryuken (神龍拳, God Dragon Fist). Upon inputting the command, Ken shouts, "Take this! Shinryuken!", and jumps up into the air with a powerful uppercut, causing a large geyser of fire to erupt around him. Any fighter caught in the geyser will be hit multiple times, before being launched away with great force.
If Ken uses his Final Smash while near an opponent, he will declare, "Gotcha!", and use the Shippu Jinraikyaku (疾風迅雷脚, Hurricane Swift Thunder Leg). Ken kicks his opponent on the ground several times, announcing the attack while kicking, before beginning to carry them upward with a rapid helicopter kick. The move ends with one final intense kick to the opponent. Similar to Shin Shoryuken, if the move has enough knockback to KO the opponent, an intense orange background from Street Fighter IV will cover the entire screen, while the final kick causes black ink to surround the opponent while violent action lines focus on the Final Smash's victim. This move will ignore edges entirely, continuing past them even during the grounded section. If Ken misses, he will instead simply perform the initial five hits of the attack.
Similar to Ryu, Ken's usage of two Final Smashes resembles a similar mechanic in Ultra Street Fighter IV, where two Ultra Combos can be used at the cost of damage. The change in animation based on proximity also matches the way certain Ultra Combos functioned if landed with the initial hitbox. Ironically, Ken's Shinryuken in Street Fighter IV had a proximity variant that led to several kicks, similar to its appearance alongside Shippu Jinraikyaku in Ultimate.
The Shinryuken is a rapid vertical Shoryuken created and used exclusively by Ken. It debuts as one of his Super Combos in the Street Fighter Alpha series, and has since appeared quite frequently, being an attack in every mainline Street Fighter game.
It also appears as his second Super Art in the Street Fighter III series, and his first Ultra Combo in Street Fighter IV. The move also appears as one of Violent Ken's Hyper Combos in the SNK vs. Capcom series. In Street Fighter V: Arcade Edition, the attack is Ken's second V-Trigger. Masahiro Sakurai states that the move's inspiration draws from that of Marvel vs. Capcom.
The Shippu Jinraikyaku is a a series of rapid kicks, finishing with an airborne Tatsumaki Senpukyaku. It was first introduced as the third of his Super Arts in the Street Fighter III series, and has since appeared in Street Fighter Alpha 3, Ultra Street Fighter IV OMEGA Mode, Street Fighter X Tekken, the Capcom vs. SNK series, and the Marvel vs. Capcom series. In some of these games, it is Ken's strongest technique, requiring most or all of his available meter to perform.
It was perhaps made most famous by Street Fighter player Daigo Umehara in his EVO 2004 matchup against Justin Wong, a Chun-Li user; in the final match of the 1-1 set, Daigo, with mere pixels of health, parried Justin's Hoyokusen perfectly, and won the match by countering with Shippu Jinraikyaku. This moment, colloquially referred to as "Evo Moment 37", was even referenced in Ken's reveal trailer, where Ken perfect shields Little Mac's attack and then follows up with Shippu Jinraikyaku. This is further referenced by his pose when initiating the move, which resembles the pose for parrying in Street Fighter III.