WARNING: The following contains major spoilers for Boruto: Naruto Next Generations #43 by Masashi Kishimoto, Mikio Ikemoto and Ukyo Kodachi, available in English from Viz Media.
When Kara first stepped out from the shadows in the Boruto manga, it seemed like a modern version of the terrorist cell led by Obito Uchiha, the Akatsuki. Among Naruto's deadliest enemies, the Akatsuki wreaked havoc by putting events into motion for the last ninja war through the hunt for the Tailed Beasts, and Jigen's crew certainly felt like spiritual successors.
However, while the Akatsuki was focused on assembling the Ten Tails monster, Kara has one of its own, chained and waiting to be unleashed. In Boruto: Naruto Next Generation #43, however, just as Koji Kashin makes his big move to destroy Jigen's group from the inside, a couple of new revelations come to light: There's not only another spy within Kara, but Jigen also has another assassin who may be just as powerful as he is.
Following the fight against Naruto, which left the Konoha Hokage imprisoned in a secret dimension, Jigen is recharging at his lair. Koji heads there and, when he realizes his boss is vulnerable, he decides to strike. He actually passes Amado, the science chief, who relays news that Jigen is at 10 percent, and Koji tells him the time to kill Jigen is now. Although we don't know why he wants to kill Jigen, Amado is fine with the plan; indeed, he has been working with Koji all along.
A mysterious character, Amado is responsible for creating vessels for Jigen to inhabit, with Kawaki representing the culmination of his work. He viewed the boy as a son, and while the rest of the villains treat him with disrespect, he serves as sort of a father figure. Amado takes each of them to heart, and doesn't want to see them die -- not simply because of the wasted work, but because they're his "children." Jigen promised Amado something when the mission is accomplished, and fans have speculated that Jigen may hold the power to resurrect Amado's loved ones once the leader achieves his full potential as Isshiki Ōtsutsuki. However, there's always the possibility Amado could turn and betray Koji, as we don't know the extent of their secret partnership.
As for the next powerhouse in Kara, Code has appeared in fleeting glimpses, teasing Delta following her defeat, and basking in Koji killing Victor. He seems to enjoy such conflict, because it establishes who is stronger.
However, Code has been kept in the dark a lot, and clearly he's being held back for a significant purpose. That's hinted as Amado reveals Code is with the Ten Tails in another secret dimension. We got a glimpse of Jigen and the monster in the past, and it's no easy creature to chain down. Code being there, guarding and possibly training it, speaks volumes about the young man.
Only powerful shinobi can undertake that job, and no average ninja would be given the task of spending time around the Ten Tails. It's an honor intended for the elite.