Kyokokukamusari

@yamatama: upper moons like that of Kokushibo can absorb their opponents for power as well. Additionally after seeing he training arc with Denji and power it was shown that I’d devils loose too much blood they will die. And drinking demonic blood isn’t an option as I pointed out in another response

@grandtoaa: yes the more blood the more powerful. The cells convert overtime when the demons body is strong enough to increase the concentration. However, none demons will if given too much at once will melt form the bones outward through complete biological disintegration

@grandtoaa: you can’t drink the blood of a demon unfortunately otherwise you’ll undergo complete biological destruction. Muzan’s blood has show this in the manga. As upper moon 1 Kokushibo posses the most amount of Muzan’s blood and thus Denji can’t drink it for power