Does he not have to pay taxes on that 1m euros in the eu?

Absolutely. That is either "Teileinkünfteverfahren" (60% of 1 Million EUR are taxed, 40% are tax-exempt) or "Abgeltungssteuer" (Government takes a 25% cut). Fun fact: there is no tax on winning the lottery in Germany!

Loto is well-known (in France) as the poors' taxes

Only if you lose (not win) :) (irrelevant side node: poker is treated as skill based game in Germany, hence you have to pay taxes on wins)

You pretty much pay taxes on everything in the EU. In Germany there are ways you can reduce the total tax you have to pay and as far as I know you wont have to pay social security contributions on that. It'll still be 6 digit tax amount.

Sure he does. He lives in Germany. They are gonna rip that 1 million apart.

Some countries have 0 rate if sold after x years. Although many had it in the past, they’ve started eliminating it.

And some countries have the opposite - they tax your invested gains as if you turned them to cash

I guess top rate in Germany is 45%

If you live in the west, 47.5% even. But that's income tax, whether that applies here depends on how it's structured.