Here's my go at the assassin you wanted, although it's still very unfinished.
The tiger stripes represent his ability to camouflage into his surroundings to remain unseen, and his eyes glow with a bright, white light which is the only part of him able to be seen at night...
To do list:
The other half of the design, maybe more stripes?
Weapons: a curved knife and a cross bow
A talisman for luck, a scarf tied around his tail?