Mushoku Tensei With the Big Fat Fish

The full title of this book is: After arguing with someone on Bilibili about Mushoku Tensei kids, I transmigrated straight into Mushoku Tensei to put my theories into practice, gave up all of Rudy's cheat abilities and talents, even gave up his face, brought along a giant fish that does nothing but freeload, and teamed up with the Man-God to pull off something earth-shattering.