Well earlier you said you could live the entire year in a country, and even in you last post you couldn't seem to figure out if you needed to hop between countries every 90 days or could just use your Schengen citizenship to stay in France all year. The bottom line is that you can't live in France, or Spain all year and claim that all your income is taxable in Bulgaria and not the place you lived when you earned it. I'm glad we agree on that.
Now, let's say you're one of the few people who are happy to hop from country to country every 90 days all your life to pay less tax and have a family situation that will tolerate that. This is really no different from a legal perspective than living in one country all year, it's just more obfuscated and difficult from an enforcement perspective. If, as you said multiple times you didn't spend a day in Bulgaria, you earned that income while physically in another country. Under the laws of that country you owe tax to that country on the income you earned while physically there. That's been well established through case law and some cute sea lawyer explanation that you actually made the money in Bulgaria because you routed your orders through a broker there, or you were really just a tourist, or anything else really, isn't going to cut it. You can't live in 4 places over the course of a year and tell each one that you earned your million euros in a 5th place you never set foot in during that year. Or like I said, you can try it but good luck.
There's a big difference between doing something legally and doing something that's difficult to trace and you may not get caught for. I don't judge you for the latter, just don't confuse yourself into thinking you're doing the former. Or even worse get someone else to take a risk they're not aware they're taking.