Clause elements

[nur]

I have another doubt here. In the sentence below:
He was the first to react.
Is the first to react a complement, as it describes the subject, or is it an adverbial, as it describes when the subject reacted.
Thanks, in advance.

[Tdol]

I'd say it's a complement.

[nur]

Thank you for the help, tdol! : )

[Tdol]

You're welcome, Nur.