Yes it's made by me. Took me whole day because of the background details. Originally I had only drawn Daki but the backdrop kinda felt empty so decided to add the Red Light district overview. Drawing different facial expression is still a challenge for me.
Yes I do use different sizes of pen tip to ink 0.1, 0.3 and 0.5. It just that I struggle shading with ink pen and can't exactly find out where the light source casts the shadow. As you can see from Saitama's face 😅