Buy CNY for USDT on Binance, then transfer the USDT to Kraken. Withdraw USD/EUR directly from Kraken to card A, then from card A to card B. Deposit funds into a brokerage account from card B. Theoretically, your CNY comes from other bank cards, which in turn come from currency exchange, and the foreign exchange comes from Kraken. Kraken's funds then come from Binance. Binance's money? Of course, it's from your trading, arbitrage, DeFi, and previous savings.
However, since you've already converted it to USDT, you can also trade US and Hong Kong stocks directly on the blockchain.