Grumpy oldman..
of reading
2696
Read books
I've watched hundreds of knife making videos on youtube. It never gets boring.
Who cares.. All these mc's, their targets start out as Grayfia-Rias-Akeno and then they get stuck on these aika-type side missions. I bet you'll join the kendo club in future episodes and develop the side characters in kendo too. I remember that human magic in dxd is done with calculations. Your parents are billionaires, tell them about the supernatural side. Ask them to research a magic book. Try to learn senjutsu. Do meditation, maybe the system will help you learn it.
Even the name of the system is 100XL or something..