The film received generally mixed to positive reviews. IGN gave the film a rating of out of 10, saying " Son of Batman finds the humor amidst the more adult-oriented action elements in this latest DC animated adventure".  On Rotten Tomatoes the film has a rating of 75% based on 8 votes.  Common Sense Media gave the film a 4 star rating out of 5, stating "Violent and noirish Batman is engaging but cynical".  Conversely, Brian Lowry of Variety stated "at times this feels like a sitcom premise — a chop-socky "Full House", or maybe, “Full Cave”".  Tommy Cook for also gave the film a negative review, commenting "Striving for the dark edge of what I guess people expect from a Batman movie while still maintaining that Saturday morning toon sheen, the film feels mass produced to appeal to all (give the adults – gore; the kids – a spunky child sidekick.); however in the effort to appease everyone, SoB in fact caters to none". 
Thalia Grace is the daughter of Zeus and Beryl Grace, a TV starlet the god met in the 1980s. She was born on December 22, 1987, 7 years earlier than her brother Jason. In The Lost Hero she is revealed to be the older sister of Jason Grace.  Due to her mother's abusive nature, Thalia has considered leaving home since she was little, but stays to protect Jason from her mother's antics. However, when Jason is apparently killed during a visit to Sonoma (in actuality, he is merely presented to Hera), Thalia finally runs away at age 10 and stays with Luke and Annabeth until they meet Grover Underwood when she is 12. When the party reaches Camp Half-Blood, Thalia gives her life to hold off pursuing monsters on top of what would later be called Half-Blood Hill. To save Thalia's life, her father transforms her into a pine tree. Her spirit then provides a magical barrier that protects the camp until seven years later when it is purged from the pine tree by the Golden Fleece .