i like ryos chart but id see some elementals in some different ways. i also have some ideas on what some elementals should have at there disposal and what not.
-Fire would have some affect to earth if the earth u mean is plant life and stones and such that actually exsists on the earth
-Water has alot of an affect against fire since we actually use it to stop most fires (usually not ellectical)
-Ice would work well against earth type elementals since it causes them to lay immobal due to freezing.
-wind how is wind feed by ice fire and earth and how would wind be harmd by most elements the way i c it fire would only use up the oxygen in the wind wich would cause the person who controls the wind (if they use the wind from around them and breathe oxygen) to sufficate, if they do not they may use there wind powers to controls the gases in the air they use to attack to contain the fire and kill it off by usiing little oxygen in the gass so the fire cant feed off off them
-earth i have nothing really to say for earth but to be more specific about how it will be so that i can critisize on what would be cool to see in it
from my point of view
-lightning this would be a interesting element. Would you try to include some
thunder elementals where as if they would work together they may enhance there powers.
also i was wondering if you master your element you would be able to learn the arts of another element like a sub element powers wouldnt be as strong as someone from the element that started with that element, maybe it would bring down the affect of the elements that we wanted o be week against such as starting with a lightning class and subclassing with earth