Other things Dell can do: Carry people. Um. Y'know buttons..things on floors? Dell can carry people/objects and drop them on the buttons to open doorways/release water gates and such.
Good ideas, I'm getting it.
And Rush...isn't he earth oriented? I'll have to look it up.
Making pillars of earth shoot up out of the ground sounds really cool.
Earth-Water would be like a mudslide effect. Not poison, unless you want to combine water-air... actually, i don't know how you get poison from the two... Maybe air has a poison effect of its own, that can illiminate a group of plant obstacles, but Poison Water only effects really big obstacle things..like sleeping monsters..I dunno. Hell.