Thinking about how she could manipulate the blood shed by her opponent, one might assume Vanessa would use a slashing weapon to cause multiple shallow cuts, encouraging bleeding. However, the weapon she conjured was not intended for a drawn-out battle but rather for a precise, technique-driven short exchange.
A rapier is designed for delivering decisive hits to an opponent's vital points with swift thrusts, straight to their body, which are much harder to parry compared to slashing attacks. In essence, Vanessa was aiming for a quick resolution rather than a prolonged fight.
Considering her current state, along with Aster's, Faeloria's, and Cassy's, ending the fight swiftly was in everyone's best interest.
*SWISH!*