...Yu-Gi-Oh!
Characters
Yami Bakura

EVIL!!! But very 
hot! And I'm not the only one who thinks so.  Actually Yami Bakura is 
somewhat of a puzzle.  At first he seems like a total creep; he's cold, 
unfeeling, angry, takes pleasure in hurting others, wants to take over the 
world.  He's a 5000 year old Egyptian thief.  He has more of his 
memory than Yami does, but not all of it. He was evidently a very skilled thief 
and had a hard childhood. As the show progresses he seems less evil, but that 
might just be because other villains are more evil (that or I've been reading 
too many Dark Bakura + Tea fanfics.) Whatever his reasons, selfish or not, he 
does protect Bakura, though he also hurts him (cuts up his arm).  We'll 
just have to see how he turns out.   
I've
read that in the Memory arc we learn that his name actually is 
Bakura, just like his host's.
Oh! And he is the only 
villain that appears through the entirety of the series.  The others belong 
to a specific arc.
      Age: 5000+
    Millennium Item: Millennium Ring
    Hikari: 
Bakura Ryou