Creating a parallel financial system will take decades if it's even feasible at all. The entire global economy relies on the US/UK/EU based financial system and has evolved around it for over 75 years. It's not something that can be simply torn out and have a drop in replacement like a software system.

Any alternative system would likely be based in China and that would mean that currencies would be backed by China's debt. China would need to take on debt levels that would leave China in an impossible situation. It would mean crushing levels of taxation that would drain China's wealth to the benefit of nations like Russia. There would be a major imbalance in payments. Russia and other nations would make net gains and China would have net losses. Even seizing assets in these nations China would need to sell the assets internationally using the same US/UK/EU system that provides the liquidity and access to markets.

It would require China to become even more reliant on business with Western nations to fund this system making the whole thing illogical and circular in structure. If the Western nations pulled out of Chinese manufacturing it would mean the US/UK/EU could collapse the whole parallel system over time and make it insolvent.