You Do Need power plug adapter while traveling from Pakistan to Swaziland.

Here is Why You Need An Adapter

The outlet and plug type used in Swaziland is M and in Pakistan are C and D. This is how they look like.

Pakistan

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

Type C

Type D

Swaziland

In Swaziland, outlets of type M are in use.

Type M