Bennie advised Sierra to speak with Robbie. According to Bennie, Robbie could help with the Mural.
Robbie at the party told Sierra to run. Robbie should be trusted because he knew enough about the Shadownshapers and agreed to help Robbie to finish the mural.
Going by what Grandpa Lazaro told Sierra, there is a connection between the completion of the Mural and the extinction of the Shadowshapers.
See the link below for more about questions on Shadowshapers:
https://brainly.com/question/25793030