My foster parents taught me a few incredible fundamentals which held true for so long. One was: To give and to receive, never take. Don't think about taking what is yours, only think about keeping what is yours.
I bow down to my foster parents' incredible honorable and intellectual power. And they were simple ordinary folks. There are incredible people hiding in the society.
About Martial Arts, when I was the teen, I took short cuts and study special force's Martial Arts such as destroying opponents eye sight, knee caps and groins. Basically if the opponents cannot see you, are immobilized, or stunned, you get advantage.
Later on, I was formally train in Karate so that I could be nicer to my opponents, to fight a more controlled fight. I learned a saying, "Don't exert all the effort to destroy your opponents because tomorrow, he might become your ally."
After I got Karate down, I adapted a few moves from Wing Chin for close combat skirmish, from Muy Thai for close combat brute power. I really like the way the Muy Thai use the leg shins, the strongest bones in human body to strike. Of course, my basis is always still with the snapping and chopping power of Karate.
Bruce Lee's system of Jeet Kun Do was to express oneself. My personal system is to 50% at expressing myself and 50% at adapting to my opponent's weakness. I personally don't believe in high kicks and always keep my kicks below the waist, but for some short opponents, I would not mind to risk a high kick to destroy his side of the skull.
If you punch fast enough, you transfer all the kinetic energy into a huge concussion which is easily break apart the fragile small blood veins inside your soft organs. Your opponent won't know it, but weeks later, the internal bleeding will kill the guy.