-----
What Erika's mother talked about was mostly the basic mission. I'll go deeper and just save the entire Kingdom while I'm at it. Of course, most of it is in ruins now. But the capital has become the demon's nest, with the ruined castle being where the Demon Overlord is located.
I'll just have to flood that entire place with my strongest summons, crush every single demon, destroy the demon gates summoning them, and then, destroy the Demon Overlord.
It won't be easy, but I was never expecting it to be easy anyways. It'll be a good test for our strength, and it'll be the ideal place where I can earn the levels I need to Rank Up too.
"So you'll be joining us, mom?! Nice! That'll make things much easier." Erika celebrated.
"I-I'll also make things easier!" Evelyn complained. "I'm strong… you know." She sighed.
"O-Of course! Miss Evelyn too!" Elizabeth celebrated.
Check "The Protagnist's Sister Is Actually the Strongest"!