Nix
Sly
din
A three-letter word ending in "ux" is "lux," which means a unit of illumination or light.
A three-letter word that means "exist" is almost always "are." See if it will work.
Eat.
The three later word that means view is see.
A three letter word that could mean clever is sly.
Observe means to see.
Sly
ilk
apt
din
Ban
See?
see
hit
one