Comments of chapter undefined of Mushoku Tensei: A different path

The manipulation....

I don't understand how Rudeus has the Dragon-Part ? Rudeus was able to have this large Mana-Reserves due to his Laplace Factor from Demon-God Lapalce & his early training. It would've been more sensible if Rudeus's Laplace-factor got further expressed & he got these abilities of Demon-God Laplace: Strong Physique without Touki (God-Rank potential), Longer Lifespan (200 to 1000-years), Higher Mana Senstivity & Demon-Tracker Eye. Rudeus should've gained these abilities from his Human-Side, Touki & faster learning potential.