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

Here is Why You Need An Adapter

The outlet and plug type used in Seychelles is G and in Sudan are C and D. This is how they look like.

Sudan

In Sudan, outlets of type C and D are in use.

Type C

Type D

Seychelles

In Seychelles, outlets of type G are in use.

Type G