16If anyone sees a fellow believer committing a sin that doesn’t lead to death, he should ask, and God will give life to him — to those who commit sin that doesn’t lead to death. There is sin that leads to death.
I am not saying he should pray about that. 17All unrighteousness is sin, and there is sin that doesn’t lead to death.
Sometimes I don't pray for people, much less the devil. That's not what praying for our enemies means.
We ask God not to lay it to their charge that persecute us even to the death because we want them to have a chance to repent in this life.
After death it is too late. And for Satan he dwells in the spiritual realm of the "too late' His charges are already laid against him and his final disposition has been determined, the Lake of Fire.