Charden's power of Tao is called "Blood" and likely comes from his liking for horror fictions. He is able to control his own blood like a limb and he can shape and manipulate it as he pleases. He uses it to create blood figures, usually shaped like skeletons, skulls or Grim Reapers, which he uses to attack his enemies with claws or a scythe, depending on the form it takes. He can also creates blood replicas of himself, through which he is able to see and talk, or streams of blood with which he binds his enemies, often squeezing them to death. Charden can turn his blood into acid, which he does when performing his "Bloody Rain" technique. (Countless drops of acidic blood which he hurls in every direction and is very hard to dodge, even for a Chrono Number.) He can also make his blood figures go underground to form a network of bloody Grim Reapers that surrounds his enemies and attack them from every side.
Charden is a highly powerful warrior with a truly dreadful power, but using this power doesn't come in handy, as he needs to cut himself to activate it, and cannot use it as freely as the other Apostles. Moreover, Charden cannot use his blood when it is not linked to his body. To compensate this, Charden can absorb his victims' blood through his own, which means that when he strikes his enemies, they are already as good as dead. Also, because of all the blood he has assimilated, Charden has an amount of blood way over the usual quantity at his disposal, making his "ammunitions" close to limitless, and rendering him very hard to kill through blood loss. Because of this, it is very likely that wounding Charden would only increase his access to his weapon. In the manga, shooting the blood figures with a gun is useless, while in the anime, Train Heartnet often destroys them with a single bullet.