I was invaded by a kind gentleman who dropped a chaos shortsword +5 and a twin humanities.
I thought he was going to rape me so I jumped at him as soon as he got close but he stepped back and stopped moving, so I watched him for about 10 seconds with my shield up when he just stood there. Suddenly he dropped the sword and moved away from it. I just walked over and took it, then he dropped the humanities, waved at me and disappeared. What a weird invasion.
I suck at this game, and I'm currently being raped by Gargoyles, but I probably wouldn't have come this far without that sword.