But for various reasons, they entered two opposing colleges. Moreover, Lily got to know Porter and others after entering Gryffindor. Potter and Snape are at loggerheads. They often fight and abuse each other. The relationship between Snape and Lily has also dropped to freezing point, but Snape still loves Lily. Snape is at Slytherin College. At that time, he admired Voldemort, and he joined Voldemort's school. Voldemort wanted to kill the child born at the end of July, and the Potters died to protect Harry. Snape felt guilty for not protecting Lily.
The patron saint spell is a reflection of the inner self and can be changed. Lily's patron saint is a deer, and Snape's patron saint has always been a deer, which shows that he has always loved Lily, always wanted to protect Lily, and also wanted to protect Lily's children. This also means that he will stand with the Order of the Phoenix, so Dumbledore will believe him and let him be a spy.
The patron saint of Harry's parents is a deer, because his parents love each other. Harry and his parents have the same characteristics, which is considered to be a kind of inheritance. His patron saint is also a deer.
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The patron saint spell is a common spell in the British series Harry Potter, used to resist dementors. When issuing this spell, the magician needs to concentrate, think about the happiest thing in his heart, and say "call the guards of God". A magician can summon his patron saint through the patron saint spell, and let the patron saint accept the attack instead of himself and launch a counterattack.
It can not only summon its patron saint to drive away dementors, but also be used for communication (that's what people in the Order of the Phoenix do because it's safe). Patrons are generally silvery and translucent animals, like ghosts in the fog. Its shape varies from person to person, which is related to the wizard's character and physique. The patron saint is not eternal, but will change when he is hit hard and his mood changes greatly.
Harry Porterie, the only death eater with a patron saint is Severus Snape? . The reason is that severus snape turned to Dumbledore before Voldemort fell. Although he is a spy planted by Dumbledore beside Voldemort, he is still a member of the Order of the Phoenix, so he can cast the patron saint spell.