If Four Is A Party This Is A Public Party

I have one too many personalities,

I don't know which one is me,

So if I'm nice at first, and then I'm mean,

You just met Sally, and then met Steve.

Yes, it's strange, but don't be alarmed,

Steve and Sally cause no harm,

Neither does Sarah, or Sammy, or Stu,

But Darwin and Devin and David sure do.

Be cautious around us,

The villains I named,

You won't know who's who,

We all look the same.

Half of us would hug you,

And falsely reminisce,

But half of us will kill you,

So in this cell, we sit.