[Discussion] Which Dragon Slayer Magic type would y'all say has the most abundant element/attribute for them to consume?

Since, a Dragon Slayer being able to 'eat' their element for replenishment is one of the notable features that distinguishes a Dragon Slaying Magic of an attribute from their mundane attributed magic counterparts.

Of the ones I can think of, it'd probably either be Sky Dragon Slayer Magic or White Dragon Slayer Magic given how abundant air and light are respectively given how they're likely to be most places one would find themselves unless magic were involved to remove the air or light from an area.

But if you disagree, let me know which one you think has the most abundant/ubiquitous element/attribute?