Crimson Rite Spell
I created this spell for a subclass (Sanguine Mother patron) of the Occultist, the newest class of my TTRPG. I will not include all the text, just the general idea.
It deals 1d6 + Awareness Modifier (damage die increases later) damage to a target. As a secondary action, you can form a blade from the blood coming from the targets wounds. This blade causes the initially rolled damage every single time. Of course, you have to keep spending some mana to maintain the blade, but this is the base idea. What do you think?