with a herniated disc in his lower back, which would require surgery and sideline him for a significant amount of time. After this injury, Archer changed his Blackout finisher to avoid a future injury. Instead of a sitout reverse crucifix powerbomb, he began to perform a reverse crucifix powerbomb. Archer returned from his injury at G1 Finals on August 13, when he and Smith attacked IWGP Tag Team Champions War Machine (Hanson and Raymond Rowe) and Guerrillas of Destiny (Tama Tonga and Tanga Loa). On September 24 at Destruction in Kobe, K.E.S. defeated War Machine and Guerrillas of Destiny in a three-way tornado tag team match to win the IWGP Tag Team Championship for the third time. At the end of the year, K.E.S. took part in the 2017 World Tag League, where they finished with a record of five wins and two losses, failing to advance to the finals due to losing to block winners Guerrillas of Destiny in their head-to-head match. On January 4, 2018, at Wrestle Kingdom 12 in Tokyo Dome, K.E.S. lost the IWGP Tag Team Championship to Los Ingobernables de Japón (Evil and Sanada). In June 2018, the K.E.S. made two appearances for American promotion Ring of Honor (ROH), who has a partnership with NJPW. They lost to the Bullet Club on June 15, and the Briscoe Brothers on June 16; the latter match being for the ROH Tag Team Championship. Then K.E.S. competed in the 2018 NJPW World Tag League in December 2018, ending with 18 points, therefore failing to advance to the tournament finals. In June 2019, Smith left NJPW, disbanding the K.E.S. and leaving Archer as a singles competitor. Shortly afterwards, Archer competed in the 2019 G1 Climax, his first participation since 2014; he participated in the A Block, with a final standing of 6 points, failing to advance to the finals. At King of Pro-Wrestling on October 14, Archer replaced Jon Moxley to defeat Juice Robinson to win the vacant IWGP United States Heavyweight Championship, his first singles championship in NJPW. He successfully defended the championship against David Finlay at Showdown in San Jose on November 9. Archer lost the title to Moxley in a Texas Deathmatch at Wrestle Kingdom 14 on January 4, 2020. On February 26, Archer signed with All Elite Wrestling (AEW) and his profile was removed from NJPW's official website, signaling his departure from NJPW. He later