Perhaps some agree that Malthus is the sliest demon; it targets the weak like a virus. However, it is undeniable that many methods are used to wear it off. Nevertheless, most demonologists would agree that this entity is probably the most powerful yet malevolent one. Vasculisius's origin is still unknown to demonologists, or how it even got to the main realm. All we know is this demon targets anyone and can form religions.
Vasculisius is omnipresent and telepathic, so it can easily persuade religious people into believing it's the right God. It can talk to several people at once, forming relationships with the victims. The people will easily believe it is God because of the voice they hear. At first, Vasculisius would give them loving advice and even make miracles happen to them. The people would believe it is truly the God they're worshipping. Many would abandon the mainstream religions for him.
However, one person in the tribe would be the scapegoat. Despite the cruelty that one person would receive, many others would still ignore the sign. The group of religious people would be led into a desert that is secluded from civilization. There, the demon would choose one person as to its target. Usually, the one person is the one with a physical or mental disability. The demon would suck out the soul of the person while tormenting it completely before using its body as a vessel. The religious people, already fully brainwashed, would not notice the sinister doing. By the time they realize it, it would be too late. People in hundreds would be forced to commit suicide.
The demon is known to target those who are gullible. It is mainly elderly people, not very intelligent people, and open-minded yet close-minded yet introverted people who get targeted. Before choosing its victims, the demon would watch them carefully from within their residence, monitoring their every move to decide if they were a fit. Not even the crucifix can fight off this God-like entity so far. However, psychics from across the world came up with solutions to prevent it from causing more harm.