[ABAJ - ???]
The veins aren't especially fortified and cutting them is a simple matter of course.
Upon being wounded, they begin to twich and leak a strange fluid colored with all the swirling colors of the rainbow onto the ground around them. The portion of the vein leading up to the basin also immediately begins to wither and die.
Two more things happen after that:
The vein begins crawling back upwards, like a grotesque worm, towards the basin again.
Mari leaps forward with a strip of cloth to quickly wipe the rainbow goo from G'nichi's sword.
"Do not let that crap get on you. It's why I'm down to only one arm.
...wasn't in the veins before, what the hell."