@Sky:
I would make anything I wanted into glass that's easily breakable.
I offer the Grass Grass fruit.
The Grass Grass fruit is a paramecia that allows me to control photosynthesis of all plants within a 100 meter radius of me, and the stronger I get with my DF the larger the radius.
Although this power doesn't seem helpful at first, it soon becomes extrememly powerful.
I actually use photosynthesis in reverse, which allows me to remove oxygen and light from surrounding area in order to excrete carbon dioxide. I ofcourse, being a grass man can survive these increase carbon dioxide levels, however my opponent isn't so lucky as they should suffocate.
Also, after removing all oxygen from the surrounding area and in turn greatly increasing the carbon dioxide levles, I can darken the area by harnessing all the light energy and carbon dioxide and shooting a concentrated beam of oxygen directly at the opponent, which should probably kill them.
The obvious weaknesses are fire logias, as oxygen is flammable and if I shot a concentrated oxygen beam at them it would explode in my face. Also, they can just turn to fire so they can see.
One day however I use my photosynthesis powers to grow the dictionary dictionary fruit.