[Vedran]

Another one. This is a spoiler:
First time In the Ice Tower I ignited four candelabras and set them in place (according to wax marks). This raised the stairs in the same room, if I'm not wrong.
Second time, I found four candles (those in the room near entrance) and lighted them as well. I pressed coloured buttons, door opened and I found the sword.
1 There are four coloured "buttons" or what on the second floor that I cannot interact with.
2 There are also locked door with a lion above it (2nd floor).
3 In the throne room there are the stairs with locked door and a distinctive part of the wall (looks like a secret passage).
4 Does the sword hilt have any use?

I do have what I need and could leave, but I will find no sleep tonight without knowing that. Please don't spoil me too much.
And don't tell me I would have to go back in that tower for a third time.