A remark / comment / humour that is sharply sarcastic is...
mordant
vivacious
jubilant
cerebral
Subtly charming in an innocent way.
tenacious
seraphic
elusive
winsome
Something that is cold and dark, tomb-like evoking dread or solemnity is...
alkaline
choral
chrystalline
sepulchral
Sticky or clingy - both physically and emotionally
stridulant
gleaming
viscid
guttural
Whispering or rustling softly (e.g. leaves, water, wind)
misty
magnetic
enigmatic
susurrant
Able to change form easily; adaptable and elusive.
Protean
Abysmal
Intricate
Convalescent
Transparently clear, either literally or metaphorically
Effervescent
Oblique
Pellucid
Murmurous
Smoothly charming.
amorphous
mercurial
suave
unflappable
Something (usually, face expression) that is dreary, mournful, bleak and gloomy is also called...
transfixing
anticlimactic
tremendous
lugubrious
Detached, drifting, without anchor - physically or emotionally
diaphanous
clandestine
liminal
unmoored
A brooding, dark expression is...
robust
verdant
lush
saturnine
This adjective is great to describe shadowy and obscure surroundings a moody scene.
dazzling
floaty
tenebrous
oneiric
Tall, slender and graceful in motion.
lissom
willowy
indomitable
assertive
An adjective that relates to light and dark contrast is...
stalwart
chiaroscuro
vivid
vigilant