Welcome to the forum, Elizabeth47!
I totally agree Humbert Allen Astredo is great as Nicholas! He gave Nicholas such suave and charm, you can't help but be drawn to him. I really love his scenes with Lara and Grayson too.
The scenes between Grayson and Humbert that I really enjoy is [spoiler]one when Julia informing Nicholas about Angelique continuing to attack Barnabas, then returns the next day to treat Adam and both scenes they play a sort of cat-and-mouse, Julia informing Nicholas she knows about him and his plans, Nicholas firmly denying everything.
when Nicholas approaches Julia about bringing Eve back to life after she was murdered by Adam. Julia won't be intimidated by Nicholas and flat out refuses, until Nicholas threatens harm to Barnabas and Adam. Julia is forced to back down.
I loved just about every scene between Humbert and Lara as Nicholas and Cassandra/or Angelique the vamp.
I really enjoyed seeing him lay the smackdown on her when she dared go against his orders.[/spoiler]