You Do Need power plug adapter while traveling from Chile to Kiribati.

Here is Why You Need An Adapter

The outlet and plug type used in Kiribati is I and in Chile are C and L. This is how they look like.

Chile

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

Type C

Type L

Kiribati

In Kiribati, outlets of type I are in use.

Type I