These are so random 😂😂

Tattoos

On a dare, the ninja and some of the other elemental masters, got tattoos to celebrate their win of defeating the Chen's Anacondri army, celebrate Zane's return, and as a way to distract Lloyd after losing his father.

The ninja had to get tattoos in places that were not normally visible or detectable by Master Wu.

Kai - His elemental symbol on his left peck.  He drank a lot beforehand, but still cried like a baby when he got it.  Jay has a video.  Kai will never live it down.

Zane - Since he doesn't have "real" skin, he got his elemental symbol etched on his lower back, right side.  The rest were mad it didn't hurt him.

Cole - His elemental symbol on the outside of his upper thigh, left leg.  He took it like a man. Kind of.

Jay - Jay lost a bet to Cole who got to pick the location of his tattoo.  Cole asked the tattoo artist to put it in the most painful but least visible location.  Thus Jay got his elemental symbol on the "v" muscle next to his left hip.  Surprisingly, he didn't make a sound.  

Lloyd - His elemental symbol above his right shoulder blade.  It a little bit reminded of his father's tattoo.

Nya was not part of this dumb-assery. 

Ethnicity  

I see them all as Ninjagan, which is a blend of East-Asian cultures.  I guess I've started assigning cultural aspects to them in my writing to help organize their tastes and preferences.

Jay - Korean

Cole - Northern Chinese (Mandarin)

Zane - Japanese

Kai and Nya -  Half Southern Chinese (Cantonese) / Half Vietnamese

FSM / Garmadon / Wu - Northern Chinese

Misako - Japanese

Lloyd - Half Chinese / Half Japanese

P.I.X.A.L - Japanese

Skylor - Northern Chinese