hahah MC is a completionist so he MUST complete ALL Achievements no matter the price 

Sum up of the chapter (made by basing myself on the novel so it might be a little bit wrong on some points):

After placing so many blocks / building so many things, Kosuke gains a new ability: He can now copy/paste a chunk of a wall or a whole building at once (blueprint function). No longer need to build one block after the other. Meaning that he can build a fortress pretty quickly now, as long as he has the materials to do so.

As they're now closer to the old Merinard Kingdom's borders, they start sending some recon units to investigate the situation. However eating is important: The units won't be able to make a fire (or it warns the enemies) = they can't bring any food that required heating (for now) so Kosuke makes them some block cookies.

There's also another problem that Kosuke and all males here have to deal with: Women. There is faaaaaar more women than men due to the previous war. And as there's a lot of different sub-humans, there's always one group that is in heat. Sykes, the ape-man who is also a member of the R&D group, was nearly kidnapped. So in order to not be killed by snu snu, males tend to stick together. Kosuke is a bit surprised by this as he has yet to experience it... but that's because he's Sylphy's man. And there's already a group interested by him (Isla, Melty, Shumer, Gerda, Pirna & lot more) so others tend to avoid him. Little fun fact concerning Pirna's race: Harpies tend to pick one husband for the whole group.

After that the first recon groups are going away.

In the meanwhile, Kosuke continues to help. He mostly goes to the R&D group. While he can do many things, it's better for them to reverse engineer what he does in order to not be too reliant on Kosuke's abilities & let him focus on other things. So we see here that they managed to create a Chu ko nu, a repeating crossbow. (The lamia also tries to make some advances on him). Then Kosuke starts to think about one important step of every building game: Automatisation. After all, it'll be nice if their ballistas can be reloaded pretty quickly. Sykes mentions the golem's core: This is a tool that can be used to execute a few simple steps. (Remember the big golem in a previous chapter? Well, their goal was to attack any unauthorized person that entered their field of view = as Kosuke covered their eyes = no vision = no reaction).

After showing their little prototype, Pirna arrives to warn them that Jagira is coming back with a large group of people that her group rescued.

Bruh, the wait for the "plot twist" is killing me.