Well I only have two OC's in mind so
Hunter Black aka Silent Night can make silver blades out of his own blood while being able to retract the blood back into his body, unless parts of the blood became 'tainted'.
Saber Slash can literilty write rune symbols in the air to form weapons or misc. items in the air, like using the words: Blade, cut, sharp, silver/gold, strong, fire, sword for a fire sword. More words added the stronger it gets.