"I'm a Romanian intern in the City of London. I'm going to work in China"

It is surprising how a person who presumably studied finance and is working in finance can still believe that China is the future.
It is also worth mentioning that Central European countries (and all European countries) have their share of xenophobic parties. Austria's presidential elections are a very recent exemple that raises far more concerns than the UK vote to "Leave".
Finally, but this is a matter of having a true democratic and civic mindset, when one moves to another country, one should look beyond mere "what's in for me?" concerns. If you only go to a country out of pure opportunistic reasons, chances are you will never feel at home and therefore safe.

1 In East Asia, British are still put above eastern European and indeed there were few Eastern European and Russian in East Asia. Please do not blame the UK which cannot do what immigrant countries such as states and Australia. BTW, wall st is dominated by the wasps as well.

2 You are so wrong with China welcomes the international students. The reason you got the internship and scholarship was China wanted to exchange for the similar opportunites in the UK. The UK is the second largest studying abroad destination for Chinese after states. So you need Britain to access as they have the deals with China.

3 You home country has little independent connection to China where a visa is required for all the foreigners.

4 Western media and certainly UKIP portray some of the Eastern European countries harming the UK and the EU in every way and the rest of the world get the stereotype from them so you can't really hide from the 'xenophobia' anywhere else. And don't forget you need a working visa in Asia and it is another entry bar.

5 Since you had been studying in the UK, you have an idea of how many Chinese/East Asian students here in the UK. The consultancy companies report China has an exess of the graduates and does not lack of the talents with the their own graduates from the top uni all over the world. Moreover, with the language barrier, they China does not really recurit investment bankers whose level are under the assossiate MD and can't bring the projects to China. Banks such as Barclay, Citi and HSBC are not very profitable in China as they are not as competitive as the state owned merchant banks. If you go to Tokyo, Hong Kong and Singapore, people there don't speak better English less French people and very often the deals are not done in English and culture will be a barrier. I don't think you will feel any less isolated if all you colleagues not talk in English in the office. People in East Asians are somehow aware of the Anglo-saxon culture and tbh foreign staffs there are either from an English speaking country (e.g Australia) or mostly French, German and Dutch as they dominate the MD in the major financial certers in the world.

6 East Asians are rather stubborn when it goes to the degree, if you did not do your undergraduate in G5 in the UK, you can't get in the top investment bank even if you are a native in the host countres.

In conclusion, I suggest you go to central Europe as there might be less 'xenophobe', easy entry, little competition and the share of the 'same value'.

"Eastern Europeans and Western Europeans shared the same values" - no I don't think Eastern Europeans have got used to notion of democracy and sovereignty and the ability to determine your own future. And that's not xenophobia.

He is unlikely to go far in Shanghai if he is not fluent in Mandarin. Plus if he considers London xenophobic, then Shanghai is going to be shocker!