mostly leaves him shooting blanks 
(ROOT (S (ADVP (RB mostly)) (VP (VBZ leaves) (NP (PRP him)) (S (VP (VBG shooting) (NP (NNS blanks)))))))
(ROOT (S (ADVP (RB )) (VP (VBZ ) (NP (PRP )) (S (VP (VBG ) (NP (NNS )))))))