Admiral Jean Decoux. I don't think he can legitimately be called a Nazi, but he sure was one of Darlan's men and a Pétainist.
Given the OTL circumstances, there was not a whole lot the Vichy could have done. Decoux was relatively new on the job and in his defense, tried to preserve whatever was left of the old colonial administration to "return" to France - regardless of Free or Vichy.
Anyways, first would be the obvious one sided battles resulting in some dead military personal and a lot more dead French colons - around a hundred thousand in Vietnam alone I believe. Decoux did not resist because he feared retribution against the civilians. Second, it will stretch the supply line of Japan just a little more (no naval and air bases in Saigon and Hai Phong) for bombings to towards Malaysia and Singapore or a safe base of operations for any South China campaigns. Long term effects in Asia are probably like...
1. Thailand treated completely as an Axis member. Instead of sparing with a weaken Vichy France - it will be grabbing much bigger chunks of Cambodia and Laos from the carcass of what is left, especially the latter. The UK forced Thailand to pay reparations and it might be more severe, possible with more territorial concessions to Burma, Malaysia, Cambodia, and Thailand.
2. Pol Pot's genocide might be butterflied away - maybe even Laos and Cambodia's communism. Thailand had much stronger claims to Laos and would be likely given much of it in the follow up treaty. Since Laos OTL was used by the French as early as 1940 as a guerrilla base against Japanese, the bases might be moved to less secure and remote locations in Vietnam and Cambodia. Given the Khmers were about halfway between the Vietnam and Laos in their independence stances, I see no reason why Cambodians would go strongly independent if the French fought with them against the Thais and Japanese. Laos was much more dependent on the Vietnamese anti-colonial movement as the Lao and French fought together against the Thais and Japanese. In our timeline, the Khmer Rouge
initially was supported by the Viet Minh.
3. Stronger Indochinese support at first but it would get progressively weaker. Many Vietnamese were confused on why the Japanese "liberators" did not break down the old colonial administration as they did with the Philippines and Burma. Since there would be nothing left to protect them, I don't see how the Japanese surely would not start forcing slave labor. As a result, there would be much more deaths on the scale of other Asian nations in WWII with resistance groups, collobrationists groups, Allied groups, Axis groups.
4. Far messier post-war Vietnamese politics. With the exception of the Catholics, most of strongest groups were either pro-Japanese or pro-Viet Minh. If Vichy resists, these Catholics would face much harsher persecution by the occupation and likely would not leave much of a base of native support for the United States to build on for the American-Vietnamese War. The religious groups, that the South Vietnamese government strongly opposed ,were many of the supporters of the Japanese during the occupation. The Viet Minh, controlled by the Indochinese Communist Party, will have a hell of harder time trying to blame both the French and Japanese and drawing support on both of them. Unfortunately, this means the religous secs and other pro-Japanese groups will play a much bigger role later on for the "liberation".
5. Hell the whole Vietnam Wars might get butterflied away. The Viet Minh were quite pragmatic (Ho was still willing to negotiate with the French until 1945 when Hai Phong was shelled). If there was any Governor-General, it would be Decoux to make concessions to the Vietnamese (he did some OTL). Vietnam was pretty screwed up badly by the French but this would surely help France's position overall in Indochina post war.
Hmm that's all I can think of now.