My Hero Academia explained All For One's new top priority with the newest chapter of the series! Although much of the climatic final fight of the Paranormal Liberation Front War was between Izuku Midoriya and Tomura Shigaraki, we started to see both mental and physical cracks forming in Shigaraki the more he used All For One's power. It was soon revealed that along with granting Shigaraki his full quirk, All For One snuck a mental part of himself within Shigaraki's body and was even able to take full control for a short time at the war's end.
Taking control of Shigaraki further, All For One freed his real body from Tartarus along with every other villain across the major prisons in the country. Now that he's officially sent the world back into chaos and hero society as it was is essentially ruined forever, the newest chapter helps explain that All For One has a new number one priority. He needs to fully take over Shigaraki's body and use to it steal One For All once and for all.
Chapter 311 of the series sees Endeavor, Hawks, and Best Jeanist going over the situation as they reveal Izuku Midoriya's new role is to act as a lure for Shigaraki and All For One. They assume the chaos is a front for the real plan of stealing One For All, but also believe All For One will soon be going on the offensive. But in order to do so, he'll need to fully hijack Shigaraki's body first.
Because All Might wrecked his body, they theorize that All For One's new plan is to groom Shigaraki as an ultimate life form. Because Shigaraki's gestation was left incomplete due to Mirko and the other heroes, and All For One is still in his own body, it's suspected that Shigaraki needs to be completely evolved for a full mind transfer to work.
This makes sense considering the last time we saw All For One using Shigaraki, he was telling Spinner that all his desires would come to fruition one "this body" gets rest and is further perfected. In retrospect that makes the fight against Shigaraki even more fearsome because if he was that powerful in an incomplete state (and still driven by Shigaraki's will, and thus holding back in some areas), what will a complete version commanded by All For One look like?
What do you think? Do you think the series is setting the stage for All For One's full takeover of Shigaraki's body? What do you think this could even look like? Let us know your thoughts in the comments or you can even reach out to me directly about all things animated and other cool stuff @Valdezology on Twitter!