OnlyTheTip
I think five is a reasonable number, but I like the idea of keeping it to three or four people (depending on the world), I suggest letting the girls stay in their world, To make it easier to control the number of girls if the total number exceeds ten, in some cases, it is possible to bring along with like Ophis (loli and cute, his children).
It is very boring. I want to say that the author gave a lot of power to the chief hero. In itself, it is not bad, but you constantly focus on how much power he gets. Considering, how easy it can get it, any choice is bored and stupid. I will not explain why it should be obvious. The matter is another, now he is just stuck for 3 months for what? Because he wants to follow the plot? What's the point?
The reason why it is called Meta Ability Creation cuz it can create "any ability" you want without "any limitations." So having a limits and restrictions to this superpower means it's not Meta Ability Creation anymore, it's more like an Advance Ability Creation cuz his power is vastly superior to normal Ability Creation.