Anime Crossover: Do I Have to Study from the Start?

After transmigrating into the world of Mushoku Tensei, I became Rudeus's twin brother?

From the start, I'm supposed to learn over 900 million magic books and more than 300 million martial arts manuals?

But that's okay. I've got a cheat!

What? My cheat is gone?

That's okay. I've still got my brain!

But I've noticed something strange about the maid, Lilia.

Where's my sister Aisha?

This isn't right!

PS: No cheating, giving girls away, or clone shenanigans in this book.

This novel and its characters are entirely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.