Do you assassins have a calling card?
In every one of my victims I leave in their pockets Nightshade.
What is yours?
Mine's been very similar to yours since Daggerfall.
My Assassins leave all of their marks with a completely empty inventory except for a single sprig of Nightshade. My way of sending their Soul to Sithis.
Bandits and other enemies that you have to fight, I don't leave this. But straight up murders count for me leaving my mark.
By my estimation, since Daggerfall, I've left behind tens of thousands of sprigs of Nightshade.