The Night Watchmen of All Realms Starting from Marvel

The protagonist has developed power, but he still has to solve problems by himself and be a nanny? The setting is a bit confusing. All the subordinates have advanced in the past, and they don't meet again until two chapters later. Our own forces can invent and produce exoskeleton armor, but how can we produce weapons? Want to find arms to arm yourself? It is set that the protagonist was very awesome in his previous life, but he behaves like an ordinary person who got a cheat!