、。。
What? Who are you? Planning to cover for them?
Literal
What, you [topic-は]. Sheltering do intention [question-か].
貴様 is an extremely rude second-person pronoun — once respectful (貴 'noble' + 様 'honorable'), it underwent semantic inversion and now signals contempt or aggression. 庇い立て ('sheltering, covering for') combines 庇う 'to shelter' with 立てる in its auxiliary sense. The clipped, aggressive delivery is typical of confrontational male speech in fiction.