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

Here is Why You Need An Adapter

The outlet and plug type used in Swaziland is M and in Syria are C, E and L. This is how they look like.

Syria

In Syria, outlets of type C, E and L are in use.

Type C

Type E

Type L

Swaziland

In Swaziland, outlets of type M are in use.

Type M