This line can be taken much deeper than one might expect. At face value you can see it as Davideo saying his blood is ink. Blood is pumped from the heart and sent through the entire body, from fingertips to the brain. A deeper look at this line suggests that Davideo truly lives his craft, and it is an all encompassing and life-giving thing for him, he puts his blood and his very life into his writing. Furthermore, to lose it (aka when it’s spilling out) would mean the death of him as an artist, just like to lose blood would mean the death of anyone as a human being.