Usage patterns
〈人〉はイラストレーターになるto become an illustrator
She says she wants to become an illustrator in the future.
イラストレーターとして活躍するto be active/successful as an illustrator
He is active as an illustrator who designs magazine covers.
フリーランスのイラストレーターa freelance illustrator
She works as a freelance illustrator.