#2 Piledriver
Dropping someone on their head tends to create one of two thoughts in your opposition's mind.
One: "I'm going to kill this guy" and two "am I paralysed?". The reason for this is that the Piledriver is commonly known for being one of the deadliest moves in the world of professional wrestling, which is probably why it's been banned in promotions such as the WWE.
One small botch or slip and it could be all over, and that's not an understatement.
In a world of takedowns, like we see so commonly in MMA, it's not out of the realms of possibility to see someone drop another fighter on their heads in an inverted Piledriver motion. Hell, if they were skilled and strong enough they'd probably be able to pull it off perfectly - which is rather worrying, to say the least.
From one evil finisher to an evil submission.
