Arg stuck again

I am in the castle and I've found 3 evil element (armory, gargoyle chain and D'soto room)

I didn't find any gnome (abriden) and vampire (lysandra)
where are they?
they have the 2 missing element I need?

I've read abriden is Est of castle, but I didn't find him..

Where to go when I have 5 elements?

Thx you in advance, I'm really stuck!
(and my english very bad)

Lysandra was halfway up the steps from the water area as you went on your way to D'Soto's room. Between the room where the outside reloads and the pool where you had to open the grate to enter.

Ardibren actually appears inside the castle, but only to tell you to meet him Southeast of the castle (there is a minor cul-de-sac just off of the castle grounds), then he disappears from there. He told me this while I was in the middle of a battle, myself, so I almost didn't catch it.

ok I've the 5
but now I'm in the tower and where I have to use the mask & elements?
where is the circle?