I find this Youtube clip of Julien Gaudfroy. His English is already very impressive for a French speaking person, then he showed his Mandarin / Putonghua skills around 6.00 in the clip. I don't know how good his Chinese accent is as I don't speak Mandarin, but it sounded impressive.
For me, trying to be fluent in two languages is really challenging and I don't know how he manage three so well (I assume his still speaks fluent French )
I find a lot of Youtube clips show native English speakers speak fluent Mandarin, but very few clips the other way round? This may be because Youtube is banned in China and not many people can upload their English speaking demos?