Nope, they don’t need our energy. That’s a narrative people learned from channeling them and they always lie. In reality, God still sustains them and supplies them with as much vitality and power as they had before their rebellion. He makes the rain fall and the sun rise on both the wicked and the righteous. It may seem weird that He would do this but you have to understand that He is permitting this great controversy between good and evil to play out on the world so that the whole universe can plainly see the consequences of sin and straying from God’s design. In order for everyone to have freedom of choice and take their side in the conflict, the wicked have to be permitted to be wicked to a certain point. They will be destroyed at the culmination of Judgement.

The sacrifice has no effect on their power beyond you giving them permission to possess you and act through you. They demand children simply because God particularly loves children and it is a mockery of the sacrificial system set up by God that pointed to Christ. The innocence and purity of a child reflects the kind of heart He wishes for everyone to have and it is particularly insulting and evil to kill an innocent child. The more you study this stuff, the more you realize that the purpose of all the rituals is really just for them to find creative ways to blaspheme God and try to force His hand in an effort to prove to the rest of the universe that He is a tyrant and shouldn’t be trusted.