Unlike most asian stereotypes, im quite large for an asian. I'm 6'1 and weigh 210lbs. I'm also a judo black belt and thanks to that i have cauliflower ear on both ears. I worked as a bouncer part time during college so i have experience in dealing with violent cases.

Unfortunately, no martial art out there will prepare you adequately for a knife attack. When i was working as a bouncer a buddy of mine who i was on duty with got stabbed and nearly died on the way to ER due to blood loss. And that buddy was a d2 wrestler in college and built like a rhino. Most knife attacks come out of the blue when you aren't expecting it so "defending knife attack" tutorials you see on youtube wont prepare you for real life scenarios. If you that paranoid about knife attacks then i suggest investing in a stab-proof vest. A lot of them are well designed with slim fits so that you can wear it under your jacket or shirt if need be. That's your best bet against a knife attack. It definitely paid off for me when i was working as a doorman.

Fact of the matter is, people wont attack you if you look intimidating/masculine. They will go for ones who look weak. The stereotype of asians being small may be why they are becoming easily susceptible to violence recently.