abstraction
action
adult
aggression
aikido
anger
antiquity
assassin
assassinate
attack
attacker
battle
black
blade
blood
camouflage
clipart
combat
conflict
cover
criminal
danger
dark
fighter
figure
fly
furious
grunge
history
invisibility
japanese
jump
katana
killer
knife
knight
mask
ninja
past
pose
poster
red
serious
shadow
shinobi
silhouette
stealth
sword
weapon