I don't understand the rules :(
The game was designed in such a way as to give the player the opportunity to figure out its rules rather than be a game that your hand is held through. Try looking at your "Blood Loss" meter and see how it reacts when you swap between blades.
If this is not clear through the gameplay itself then we apologize, and shall try to make our games more intuitive in the future ;)
-Damon Billiot