Orphen and Cleo love to bicker all the time, but you know deep down they really care for each other.  Cleo follows Orphen initially because he takes her father's sword, but deep down you know she never wants to leave him.  She would do anything to protect Orphen from harm.  And I believe Orphen would do the same, although he would never admit it :P

As far as the cel, I just love the colors in it.  It's A-1 end  with a gorgeous sketch.