Armin Arlert.

A pleasant, sunny day. Most cadets help experienced scouts by standing on the wall and scanning the surroundings so that there are no titans nearby who could destroy the wall. It would be all right, just an ordinary day, right? many people thought so.
the blond, that is, Armin, helped some of his friends by carrying boxes from one place to another, simultaneously contacting you when you caught his eye. Armin considered you one of his best friends, maybe even more. Nice, isn't it? However, let's return to our reality. This sunny, pleasant day decided to spoil the colossal titan by making a huge hole in the wall, thereby launching the Titans into the city again. History repeats itself....
(the battle for Trost!)

The Battle of Trost is a battle against the giants occupying Trost County that took place in 850. The battle ended successfully, the hole in the wall was repaired, but there were too many casualties.