I've heard prayer warrior since I was a kid in the 80s. The idea is that the prayer warrior is fighting a spiritual battle instead of a physical one. How is it a battle? Well when they start praying, Satan will start to attack with doubts and fears. So it's a fight to preserve and continue praying.

All garbage as far as I'm concerned, but to them is has nothing to do with changing the meaning of words. It's the best way they have to describe how hard it is to pray for hours on end for multiple days when you have a brain telling you that this is silly.