Definition :
Emphatic pronoun emphasizes the noun.


I myself completed the homework.

It means that the subject itself completed the homework without anyone’s help

Now look at the following sentences:-
I will do it myself
I myself saw him do it
We will see to it ourselves
You yourself can best explain
They themselves admitted their guilt

It will be seen that here Compound Personal Pronouns are used for the sake of emphasis, and are therefore called Emphatic Pronouns

Learning Competency

Non-defining relative clause
Non-defining relative clauses are placed after nouns which are definite already.
The adjective clause which does not define the noun before it but gives additional information about the noun is called the non-defining relative clause.