There is no Bionicle set with the Mask of Time (Kanohi Vahi)! The mask came as a promotional item, but it never came with a set. Only the golden Mask of Time came in 2004 with some Vahki sets.
The is no Mask of Nothing...
Bionicle Mask of Light.
Bionicle: The mask of light.
I think so.
There is no website where you can make your own Bionicle mask.
Gelu doesn't have a mask. He wears a helmet.
There is no BIONICLE movie in 2001. You probably mean the movie from 2003 (BIONICLE: Mask of Light)
A Kanohi is the name of a mask in Bionicle. In the Bionicle story, the Matoran name of a mask is 'kanohi'. Each Kanohi has another name (eg.: Toa Tahu's mask: The Kanohi Hau).
BIONICLE: Mask of light, BIONICLE 2 : Legends of metru nui, BIONICLE 3 : Web of shadows, and the newest one BIONICLE 4 : the legend reborn.
I think you mean Nektann, but he is a skakdi, and he doesn't wear a mask!
If you have Bio-codes (you will find Bio-codes on the back of Bionicle sets), you can put these codes on the Bionicle website. If you have a few of these codes, you get your kanohi mask badge.
It is called the Kaukau, the great mask of water breathing.