You Do Need power plug adapter while traveling from Brunei to Côte d'Ivoire (Ivory Coast).

Here is Why You Need An Adapter

The outlet and plug type used in Côte d'Ivoire (Ivory Coast) are C and E and in Brunei is G. This is how they look like.

Brunei

In Brunei, outlets of type G are in use.

Type G

Côte d'Ivoire (Ivory Coast)

In Côte d'Ivoire (Ivory Coast), outlets of type C and E are in use.

Type C

Type E