Y'all might disagree but i don't like the idea of those 2 kids became permanent resident of that place. MC should've erase their memory of his place & led them to their people like the did to all of those slaves.
Your dislike is noted and relegated to the Circular File.
The MC is, for all purposes in this world either a Demon Lord, or a Living God, depending on who you ask, commanding mythical beings of the highest order.
He also does
not posess a magical gimmick to understand the local languages....
The kids are at least partway a bridge for that language gap
and a way to explain at least to the beastmen tribes that the Living Nuke flanked by living disasters is/are actually big softies. If you get to know them and don't try the FAFO thing.