Orolestes octomaculatus is a fairly easy species to recognize. 
The male is blackish with segments 9 and 10 bright blue.
It has blue-green eyes and 2 black patches on each wing (8 in total).
The female is brown with a yellowish-black thorax and has 5-6 large hooks on the underside of the ovipositor (only visible in close-up).
They like to hide under leaves.
I found this individual in the middle of the forest.

A female. Cat Ba National Park, Cat Ba Island, Vietnam, 7 January 2024