凶
=
乂
+
凵
:
Mnemonic symbol: a vicious (凶) demon mask. Xu Xian (xu) tried out an electric demon mask (凶) in front of the engine ((e)ng1), but now he can't take it off anymore. He already tried to pull the cable out of the receptacle (凵), but it didn't work. Maybe he has more luck using pliers (乂) to pull at the mask.
刀
=
㇆
+
丿
:
Mnemonic symbol: 刀 looks like a cleaver (while 刂 looks like a kitchen knife).
Don Quixote (d) serves his good deed of the day in front of the aorta (ao1). In order to feed the people, he uses a plow (㇆) to dig up bananas (丿), and cuts them into slices with a broad cleaver (刀).