I think it would be cool if at a certain high skill level and a high enough specialization would allow you to customize some of your attack messages. I'm imagining a command that would allow you to pick body parts, and then input the message. Whenever you'd hit said body part there's a chance that your custom attack might trigger instead.
The custom attacks would not change the damage values at all, just only for aesthetics.
Since a lot of people are worried about bloat I suggest a limited amount of messages, maybe one when you first get it up to maybe four or five at max level.