I know two people who I suspect are both ENFP, though they could also be outgoing (or in one case, aggressive) INFPs. Really can't quite make up my mind with either.
One of them is almost certainly mentally ill (possibly quite seriously, ie. BPD or something similar) so not such a good example, really. But she looks angry almost all the time and acts angry a lot of the time - and claims not to have a clue that she's coming across this way.
The other one suffers from some emotional instability but is otherwise ok. She doesn't tend to "look angry" as a default but she certainly comes across as intense, and I suppose that could some of the time look like serious/angry. My own face, for instance, might tend to look serious (or sometimes sad, but I got told that more when younger) as a default, but I'm a bit more impassive, I think, though my face and tone can be pretty expressive. She certainly gets angry quicker than I do, but also gets over it quicker.
Oh, and I am pretty sure she'd agree with you [MENTION=14503]disco[/MENTION] about the "darker energy" thing. She's a quintessential type 4, and has always leaned towards goth style and that sort of thing, and does tend to gravitate to situations and people which/who are dark, tragic and drama-laden.