Warning: the following article contains spoilers for 86 Eighty-Six Episode 16, "Even So," now streaming on Crunchyroll.
In Episode 15 of 86 Eighty-Six, Shin attempted to inform the Giad military that the impending Legion attack would be much larger than anticipated. However, the military found that hard to believe, and so proceeded as originally planned. It's not surprising that they didn't take Shin's word at face value -- after all, they have no idea how reliable his information is, especially since he's keeping his ability to detect the Legion a secret.
Equally unsurprising, in Episode 16 things happen just as Shin had warned. The Legion appears in overwhelming numbers, attacking countries in every direction all at once. This includes the Republic of San Magnolia, where the government continues to keep the citizens oblivious to the imminent threat.
Shin reveals to Raiden that the situation is nearly a worst-case scenario. Forces he expected to be sent to other countries are being sent the Federacy, while the Republic seems to be the most important target to the Legion. Shin urges Raiden not to connect to him during the battle unless he absolutely has to. Curiously, Shin is oddly overwhelmed in this moment, anxiously sweating with a worried expression on his face. This is a testament to how dire the situation is, as Shin's face rarely reveals how he's truly feeling.
Fortunately for the Giad Federacy, Shin and the rest of the Nordlicht Squadron skillfully take care of the Legion forces and prevent a complete invasion. The Squadron were all smiles themselves during the battle while everyone else was terrified for their lives. This shows once again that the battlefield is genuinely where they're most comfortable.
However, Shin seems to go completely out of his right mind after a while. He begins recklessly attacking the Legion on his own with a disturbing look on his face that was as if he'd been possessed by something. This terrifies Frederica, reminding her of how Kiri was. In Episode 15 she stressed that Shin and the others should run if the battle gets too dangerous, but he does the exact opposite. Even Raiden and the others are taken aback by his behavior.
Over in the Republic, the Legion attack is being kept under wraps, much like everything else concerning the war, so the public has no idea what's happening. Lena does, however, and intends to fight however she can. As Lena rushed to get in touch with the processors, she runs into her uncle, General Karlstahl. He tries to dissuade her from having the Eighty-Six enter the Grand Mur to form a defensive line before the Legion can reach District 1.
General Karlstahl believes the people of the Republic would be better off getting destroyed by the Legion, rather than letting Eighty-Six inside the Grand Mur. His reasoning is that the Eighty-Six will never truly fight for the Republic, since the Republic oppressed, slaughtered and abandoned them. They have no obligation to protect useless citizens who do nothing but complain.
Lena doesn't disagree with him, but she wants to fight anyway. She refuses to simply give up on everything and just wait to die. She would rather fight until her dying moment, otherwise, she won't be able to face those who did and believed she could too. This parallels Shin and the others' reasons for choosing to return to the battlefield instead of being satisfied living peaceful lives.
The General gives in and lets Lena do what she wants. It appears he never actually intended to stop her, he even moves to buy her time, setting off with a gun. Lena connects to all Processors in combat areas and encourages them to fight to the end. In the episode's post-credit scene, Frederica tells Shin and the rest of the group that Kiri attacked the Republic. She describes seeing a shattered wall and a burning five-color flag.
The group assumes it's all over for the Republic and asks if Kiri is still attacking. Before Frederica can finish answering, both she and Shin hear a threat from Kiri via their powers as they are seemingly attacked. It's unclear what exactly happened, but the scene ends with a cliffhanger showing Shin rushing over to protect Frederica.
