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

Here is Why You Need An Adapter

The outlet and plug type used in Monaco are C, E and F and in Seychelles is G. This is how they look like.

Seychelles

In Seychelles, outlets of type G are in use.

Type G

Monaco

In Monaco, outlets of type C, E and F are in use.

Type C

Type E

Type F