You Do Need power plug adapter while traveling from Seychelles to Cambodia.

Here is Why You Need An Adapter

The outlet and plug type used in Cambodia are A, C and G and in Seychelles is G. This is how they look like.

Seychelles

In Seychelles, outlets of type G are in use.

Type G

Cambodia

In Cambodia, outlets of type A, C and G are in use.

Type A

Type C

Type G