Answer:
Alone I am 24th with a friend I am 20. Another friend and I am unclean.
Blade to blade I always win My foe laid low and even. Yard by yard through thick and thin I'm busiest in season.
The more you take of me the more you leave behind.
I save lives on the ground and in the air
I am used for light yet I am solid. Without me you would feel enclosed. I hate being touched especially with a lot of force. I like to be in buildings.
I flow from the Homerβs mouth when he sees doughnuts.