"Adversity Makes a Man Wise" is the twelfth and final episode of Durarara!!x2 Shou and the thirty-ninth episode overall of the Durarara!! anime.
The various sparks smoldering all over the city explode into a huge disturbance, consuming Ikebukuro. The battle between the Dollars and the Toramaru; the person pulling all the strings, Aoba; Vorona’s fierce pursuit of her prey; Celty, hot on the heels of the abducted Akane; Shizuo, still on the run; Izaya, observing the chaos in the city from afar with a smirk on his face. What lies ahead for them all?
And amidst all the chaos, what kind of answer does Mikado offer?
adapted from what manga or LN chapter?
references to previous episodes?
In order of appearance (not including OP)
Mikado: "Regardless of your reasons, you got Sonohara-san involved. This is my answer to that. At the same time, this is the first order I'm giving you. Accept my fury."
Aoba: "This bloody piece of paper is our contract. From this day forth, Mikado-senpai, you're our leader. You're free to use this power called the Blue Squares within the Dollars however you see fit."