what China did is buy discounted Russian oil, blend it with Saudi oil, and sell it as refined fuel, country of origin, China, at full price.It will affect Russia 100%, although not the way people think it will.
With this price cap in place, China and India will use it as leverage to get more discounts from Russia. Countries aren't a charity, for something as important as oil no country is going to leave money on the table
That's how the price cap is going to damage Russia's finances, not directly but indirectly instead