For most anime characters, bleeding is a sign of a problem. But for anime characters who fight with blood, an open wound might be just what they need to dominate their opponents.
Many of these blood wielding anime characters take their own blood out of their bodies and harden it into weapons that they can use in battle. Others kick it up a notch by turning their blood into ice, boiling liquid, or even into a bible verse.
How they get their blood back into their bodies is rarely mentioned, and when it is, how they do so cleanly is still left out. These powers are awesome, but also kind of gross - just like the anime characters who use them. Which one do you find the most appealing?
Since he's a vampire, it's not exactly surprising that Alucard has blood-based abilities. He can do pretty much anything he wants with his and other peoples' blood with seemingly no limits. He can steal people's souls by absorbing their blood or drown people in tidal waves. Needless to say, you do not want to get on Alucard's bad side.
Shiro belongs to a group called the Deadmen, all of whom use their own blood as weapons to some degree. Shiro can turn her own blood into a powerful whip that destroys anything it touches on contact. When her body is being used by her alter ego, the Wretched Egg, her whip is so strong that it once caused an earthquake.
As a child, Crona's blood was replaced by a scientifically created substance called black blood. Black blood not only changes the color of Crona's blood but also allows them to use it in battle. Crona can harden or liquify their blood at will, using it as a weapon or a defense mechanism. Their blood can also form Ragnorok, a talking weapon that serves as Crona's battle partner. Black Blood can also destroy Crona's ability to feel fear, which lets them take risks they otherwise might not during battle.
Mirai is a Spirit World Warrior whose job is to defeat youmu, a form of mythical demon. She does this through her blood manipulation powers, which takes two forms. Her blood can take the form of a sword, a shield, or any other piece of weaponry she needs. Her blood can also be corrosive to anything it touches. Her abilities are dependant on how much blood she actually has in her body, which is part of why she's so focused on eating iron-rich food.
Despite their obvious strength, Mirai's abilities are actually considered disgusting and even heretical among other Spirit World Warriors. As a result, she's looked down on by the community.