"Cast blame upon" is a phrase used to indicate that someone is holding someone else responsible for a negative outcome. There are plenty of synonyms for this phrase, including "accuse," "confront," "charge," "condemn," "denounce," "finger-point," "impeach," "incriminate," and "reprimand." Each of these words has its own unique connotation and degree of severity, ranging from mildly accusing someone of responsibility to aggressively condemning them for their actions. When choosing a synonym for "cast blame upon," it is important to consider the specific situation, intent, and audience, and to choose a word that best reflects the appropriate level of blame and accountability.