Superman who has a lot of magic powers is our most favourite Superhero.

Explanation of relative clauses:

A relative clause is a type of subordinate clause that gives more information about a noun. It usually starts with a relative pronoun such as who, whom, whose, which, or that.

• who: used for people.
• that: used for people or things.
• which: used for things.

In the sentence "Superman who has a lot of magic powers is our most favourite Superhero.", the relative clause is "who has a lot of magic powers". It describes Superman (a person), and it uses the relative pronoun "who".