A define a gimmick in hip-hop as (and you dont have to agree with me, I dont care): an emcee who SELLS or IS SUCCESSFUL based PURELY on his or her "STAND OUT IMAGE", but has NO actual SKILLS.

Since Jin is quite a dope freestyler, and is above average in battles - I dont consider him a gimmick. I bob my head to some of his songs, and he comes of very dope in freestyles. Same goes for Eminem - lyrically dope, interesting, good delivery.

A gimmick would be:

Nelly - no skills, just attractive to women and has a weird voice.
Chingy - no skills, just invents slang words which sells.
Bizarre - no skills, just says lots of explicit stuff so kids will buy it.
Vanilla Ice - no skills, could pass for a regular bling bling rapper - but sells higher than most cos of his colour.

Notice how each "gimmick" started with "no skills"? You get the point now.

BTW, Asian Rappers? The Chosen One is dope as fuck.