The team entered the 2005 Tag World Grand Prix and ended up winning the tournament after Hero turned on his partner Quackenbush in the final of the tournament. Afterward Castagnoli started feuding with his former partner Chris Hero. (Icarus, Akuma and Chuck Taylor) to form the Kings of Wrestling superstable, which was later joined by Mitch Ryder, Max Boyer and Shayne Hawke.Together, Castagnoli, Cannon, and Hero formed the Kings of Wrestling faction. On April 22, 2007, at Rey de Voladores Hero defeated Castagnoli and as per stipulation of the match Castagnoli was forced to re-join the Kings of Wrestling. On September 22, 2007, at Cibernetico & Robin the Kings of Wrestling faced Los Luchadores in the annual torneo cibernetico match.better known by his ring name Cesaro (shortened from his previous ring name Antonio Cesaro), is a Swiss professional wrestler who is currently signed to WWE, performing on the Raw brand where he is one half of the current WWE (Raw) Tag Team Champions along with Sheamus.He was previously known for his work in Ring of Honor (ROH), various independent promotions including Pro Wrestling Guerrilla (PWG) and Combat Zone Wrestling (CZW), and the Japan-based Pro Wrestling Noah.Cannon left the promotion at the end of 2005, leaving Hero and Castagnoli to form a regular tag team. The following month Hero, Castagnoli and Larry Sweeney joined forces with Team F. The Kings won the match with Hero, Castagnoli and Mitch Ryder as the survivors, but since the match could only have one winner, they were forced to face each other. the two of them were booked in a "Respect Match" on November 22, 2009, at the season eight finale Three-Fisted Tales, where the loser of the match had to show respect to the winner.They entered the 2006 Tag World Grand Prix, defeating Equinox and Hydra, Ranmaru and Sumie Sakai, the North Star Express (Ryan Cruz and Darin Corbin), Incoherence (Hallowicked and Delirious), and finally Team Dragondoor (Skayde and Milano Collection A. (Icarus and Gran Akuma) in a two out of three falls match. Castagnoli forced Hero to tap out and then pinned Ryder to win not only the match, but also his freedom from the Kings of Wrestling. Castagnoli won the match, but instead of showing respect, Kingston attacked him, claiming that both Castagnoli and his former partner (Chris Hero) were shady and did not deserve respect.
They competed in IWA Mid-South and Chikara and received training from Hero before returning to Europe.
Castagnoli gained success in ROH singles competition on July 28, 2007, by winning Ring of Honor's Race to the Top Tournament, a 16-man, two night event.
He defeated Hallowicked, Mike Quackenbush and Jack Evans en route to the final, where he defeated El Generico.
Castagnoli is also known for his feats of strength in the ring and is frequently mentioned as one of WWE's best and most underrated performers.
He was consequently recognized by the Wrestling Observer Newsletter as the Most Underrated Wrestler in the world a record four times, from 2013 to 2016.