YoYoMack

YoYoMack is a het ship between Elena Rodriguez and Alphonso Mackenzie in the Agents of S.H.I.E.L.D. series.

First appearing together in the second half of season 3, Elena and Mack had a hostile meeting as they both viewed each other as a threat. She uses her powers to kidnap him, but Mack gets free. Once Elena realises that he is not a threat, their feelings begin to change, with Mack fondly calling her Yo-Yo—after her powers.

Canon
After undergoing Terragenesis, Elena believes that her new-found powers are a gift from God and should be used as resistance to the Spanish police, who had been abusing their status of policemen. Mack, along with The S.H.I.E.L.D. team arrives in Bogotá the next day to investigate. As Mack searches, he spots a female woman with heavy boots. The woman, Elena, notices him and instantly believes him to be a threat. Hence, she uses her powers to take Mack's gun out of his holster and points it at him. She then uses her powers to force Mack into the back of a van and kidnaps him.

To her annoyance, Mack wakes up and watches Elena with her cousin talking in Spanish. She later talks to him, but because of the language barrior; they were unable to understand each other. Mack comments that his powers are "like a Yo-Yo" However, Mack manages to convey that her powers manifested because of the fish pills, instead of God. Their conversation is soon cut short when Daisy Johnson and Joey Gutierrez interrupts and forces Elena into an S.H.I.E.L.D. containment pod.

After Joey convinces Elena that they are not a threat, Mack discusses the role their faith plays in their lives. After this, Elena begins to trust Mack. Both of them help each other to defeat Lucio.

Later, Elena apologises to Mack for kidnapping him and says thank you, in English. He fondly calls her Yo-Yo in response and hopes that he will see her soon.

Fanon
YoYoMack gained a decent amount of popularity after the eleventh episode of season 3 premiered. Many fans adored how Mack affectionately named Elena, Yo-Yo. Thus, their ship name became YoYoMack which was popularized as their ship name, immediately after the episode. Also, some fans theorized that either Mack or/and Elena are the ones in space in the flashforward scene. Fans were distraught at the idea of this and the effect it could have on their relationship.

Trivia

 * In the comic universe, Earth-616, Elena's name is Yo-Yo Rodriguez. While in the Marvel Cinematic Universe, Mack gives the nickname "Yo-Yo" to Elena, similar to how he nicknamed Daisy Johnson as "tremors".