Harbinger of Upheaval

Harbinger of Upheaval (波瀾の来訪) is the 3rd chapter of the 13th volume and the 47th chapter overall of the Attack on Titan: Before the Fall manga, written by Ryō Suzukaze and illustrated by Satoshi Shiki.

Overview
Surprised by the sudden appearance of Xavi, Kuklo and Cardina are angry that he was sent by Gloria to monitor the training program. As the training process begins, Rosa, Kai and Felix fail the test, while Ivo and Xavi manage to stay balanced. As the instructors look over the results of the training that day, Sharle goes to Xavi and see why he actually is there.

Summary
Kuklo, Cardina and Sharle are shocked by the sudden appearance of Xavi. Xavi chuckles at seeing Kuklo again, calling him a dead man and marveling at his apparent luck. He assures that he is not there to fight but to monitor the training regimen for the upcoming expedition, and if there is actual merit in keeping the Survey Corps active under the orders of Gloria. Kuklo and Cardina take umbrage when Xavi taunts them that it would be pointless if only they were the ones capable of using the vertical maneuvering equipment and none of the other members or trainees in the program. Therefore, he again prohibits Kuklo from defeating a Titan by himself. Xavi then recognizes Cardina and formally reintroduces himself, noting that he remembers Cardina from their training days. He then takes his leave to meet with Carlo, stopping by Sharle and merely states they will talk later.

As the trainees stare at the aptitude training devices, Ivo notes with concern what they could be used for. Both Rosa and Kai believe that it is an entrance test for the Survey Corps. Felix states it possibly is for the device; Kuklo then gives everyone a rundown on what the device is and how they must stay balanced. As several trainees try and fail, Ivo is the first that is able to maintain his balance. Rosa then tries and fails, followed by Kai and Felix; all three are in low spirits over this. As they overlook the trainees, Jorge and Carlo spot Xavi approaching the training area; Xavi asks Kuklo if he can try the device himself. After some hesitation, Kuklo agrees and everyone is stunned when Xavi effortlessly stays balanced. Amused with how simple it was, Xavi turns to Carlo and wishes to be introduced to the trainees. Carlo does so and many are surprised to hear that Xavi will be taking part in the expedition.

That night, Kuklo and Cardina go over with the trainers the results from the testing earlier in the day. Five have already shown they can handle the device and more will be selected during a retest taking part the following week. Although the second and third round of trainees will have less time to learn how to properly use the equipment, Carlo is still optimistic they will have a full squad in time. As the meeting ends, Cardina asks Carlo about Xavi's presence; Carlo reiterates they have no choice in the matter and the fate of the Survey Corps are in Gloria's hands. Kuklo laments that he cannot take part but Carlo says that as long as he does not strike the killing blow, there is no reason for him not to come with them. Elsewhere, Sharle visits with Xavi to see what his true motives are for being there.