headcanon i.
due to the thick viscosity and texture of mukuro’s blood, his heart beats at a horribly slow pace; thudding heavily in his chest. while the beats are extremely solid, perhaps even heavier than a normal heartbeat ( for the force needed to push his blood through his veins, ) they are extremely slow and have great pauses between each beat.
there are times where it seems like his heart isn’t even beating, giving the appearance of mukuro being dead. it usually occurs when he is either sleeping or completely relaxed, startling others when his chest suddenly rises with a breath or they feel the beat of his heart.
another thing that comes from the thickness of his blood is how slowly he tends to bleed. it takes a great amount of force to push his blood through his veins, which also comes into play when he’s cut. it takes several seconds longer for blood to rush to the open wound and well up. this comes to his advantage since internally, mukuro can handle the corrosive properties of his blood, but it does affect him outwardly.
due to the fact mukuro’s blood is also black as tar, it shows up very easily on his pale skin -- almost making him seem somewhat transparent. patterns of his thin veins crisscross underneath his skin, leaving what appears almost like someone drew on him with charcoal. it is the reason he prefers to wear all black and stay as covered up as possible, wanting to not draw too much attention to himself.