No information from CLAMP, as he's an anime-only char.

<Suu> Why is everyone looking so glum?
<Asuka> We're kinda in a bind because we're doing the
        anime-only characters.
<Satsuki> I wish I had more solid information like I
          do with the manga characters....
* BEAST purrs in apology.
<Satsuki> It's not your fault, BEAST. 
<Shinji> .... it's not much different from the fourth
         set....
<Asuka> I hate to say this, but I agree with
        BakaShinji.
<Sizer> So who is this chap?
<ChunHyang> Oh yeah.  He's the right-hand man for
            Zagato in the anime.
<Yang> He's good at *mffffff*
<Alice> *smiles* That, Yang-san, is a spoiler because
        that wasn't there when we first meet Inouva.
<Nova> He gets bonus points for pointy ears!
<Asuka> HEY YOU!  rika said none of the RE personas
        could be here! GIT!
* Nova runs away, chased by Asuka.
<Rei> ..... hen.
<Suu> So basically, he's the stereotypical "extremely
      loyal to his master, the big bad guy in the series"
      type villain?
<ChunHyang> Basically ^^;


(spoilers ahoy.  this one's small, too.)


<Alice> Yang-san, you can tell us now. ^_^
<Yang> Well, as I was saying, he's good at
       cross-dressing.
<ChunHyang> Enough to fool Ferio! *chuckle*
<Suu> Fuu, Kawaisou.
<Asuka> Fuu and Ferio made up in the end!  Don't
        worry!
<Satsuki> And he, after that plan failed, turns into
          a cute little beast!
<Shinji> He's not human?
<Satsuki> Nope, he's been assuming human form for all
          that time, but in reality he's more of a seijyu.
          A rather cute seijyu.