The outcome of the last arc had several interesting consequences. On one hand, it gave us a glimpse of the full extent of the Demon Army's top ranks, gave them a significant (but not overwhelming) power boost, and made us the readers as well as Allen and friends aware of how much the NLG are still underpowered in comparison to them.
On the other hand, it also allowed the NLG, the Allen Army, and the Alliance at large to get a significant power and resource boost of their own. Moreover, the disclosure Allen got about the enemy's top leadership and their resources and plans gives him lots of room to adjust and refine his strategies and powergaming accordingly.
For everything we discovered, there is still so much we don't know about the enemy's plans, past events before Allen's coming to this world, and the nature of the clash between the Pantheon and the Demon Army. In this regard, the hinted future visit of the NLG to the Heavenly Realm might turn out rather interesting and enlightening.
Glad to see Beku was able to redeem a wrong life with a heroic last stand and death that prevented a full success of the enemy's plan, Pelomas grew a spine from his company and example, and made himself worthy of belonging in the NLG and the Allen Army, as well as a happy ending with Fiona. She wanted a badass hero for a husband, and got her wish fulfilled. They also got to star in a romantic tale that no doubt shall become part of the legend cycle of the saviors of the world.
We can only hope that Pelomas and Fiona's example can start to make Allen aware there is more to life than powergaming, you can indulge in romance while saving the world, being a happy Battle Harem is one of the best romances and comradeship bonds there is and makes everyone more effective, and there are at least a couple close friends, fine ladies, and gallant heroines at his side that are pining for him.