Well chucks are dangerous... You can really eff yourself up with those. I would bet that chucks have caused at least 10 times as many injuries to users than any opponents.
I have a damascus one that's supposed to be able to repeatedly go thru the sheet metal of a car door, its rad. I also have tiny scars all over my hand from trying knife tricks as a youth haha, and nothing else to add to this conversation. I also should have FIGURED, but did not know, that training versions were readily available when I was younger. I could never figure the one out where you spin it over the back of your hand like a coin thru your fingers trick, but the tricks are neat.