Creating a sword entirely out of blood is not practical due to the low iron content in blood and the difficulty of shaping and hardening blood into a functional weapon.
A Victorian-era material called hematite was made by heating and pressing blood and sawdust, but it was used for making durable objects like doorknobs and roller skate wheels, not weapons.
Making a blood sword using modern materials like blood glue and sawdust composite is possible, but the resulting sword may not be as strong or durable as traditional swords.