There are two major weaknesses of this film.
First, the Blood of Jesus Christ in the container of relic. Every Christian who has read the Bible knows that when Jesus Christ was arrested, tortured and crucified by the Roman Empire, all disciples of Jesus' followers fled in fear. Around the Cross of Jesus Christ, were Roman soldiers who ridiculed him, and the Pharisees who were grudgingly against Jesus Christ, and Mary the weak mother of Jesus was frightened by John the melancholic disciple of Jesus. No person at the time of the crucifixion of Jesus who thought could accommodate or take the blood of Jesus. When the Lord Jesus Christ was crucified, no one believed that Lord Jesus Christ would rise and rule over Satan and death. When Jesus died on the cross, the devil and all the political enemies of the Lord Jesus Christ thought they had won. No one thinks that the Power of Jesus' Blood defeats the devil.
When the Lord Jesus Christ died on the cross, He died of blood. Out of blood from being tortured by Roman Empire soldiers. The Lord Jesus Christ ran out of blood when the whole body of the wound was whipped, lifted the cross, and then hung on the cross for 3 hours. That is the original idea of the death penalty on the cross, that prisoners will die of blood when crucified. This is evidenced by the Bible record, that when the Lord Jesus Christ died, the Roman army thrust the spear into his stomach which came out was no longer fresh blood, but blood mixed with water, which indicated that Jesus Christ had died, the cause was run out of blood.
The Pastor figure who should have the power to do an exorcism, just screaming in panic when there was a demon attack. There is no spiritual authority displayed in this Pastor's figure.
This film is very weak in terms of spirituality. The director and screenwriter did not know the process of exorcism and the power of the priest's ritual. If the film director wants to make a Pastor's character against Satan, watch The RITE movie first, which is based on a true story.
The NUN film is only good in terms of cinematography because of Romanian nature and monastery buildings that are spooky, but the scenario is very bad and the story is too weak