You posses an incredibly potent conceptual tie to an element of your choice, this can be something as simple such one of the classical 4 such as Fire, more esoteric versions such as Metal, or even something completely unique such as Life. Your control over your chosen element is unmatched and can be expanded to encompass elements similar in scope such as Earth is to Lava. From the moment you acquire this you have complete control and mastery over your chosen element being able to effortlessly create, summon, dismiss, shape, and control this element on an extraordinary scale such as grand tsunamis and ferocious storms, and with such immense precision that you are not constrained to traditional limitations and are able to just as easily create an intricate dress made of Metal as you would in summoning a tidal wave of Water. You are granted precise control over it’s every manifestation, from the gentlest breeze to the most intense inferno and are incapable of being harmed by it. But most importantly your ability extends beyond the physical realm. You have the knowledge and ability to use your chosen element conceptually, tapping into their symbolic representation and harnessing it’s metaphysical properties. You could utilize Fire to inflame passions, ignite creativity, drive others to anger, or use it’s connection to the sun, heat, and summer to create an everlasting summer.
Expanded Domain
In addition to whatever your chosen element is, you now also have the added elements of the avatar. Your control has now been expanded upon to include Fire, Water, Earth, Air, Energy, Lightning, Combustion, Blood, Ice, Steam, Cloud, Storm, Plants, Lava, Mud, Metal, Sand, Dust, Glass, Crystal, and Spirit and you now possess the ability, with time and effort, to add additional elements to your repertoire. Any elements, concepts, or domains that you possess or can manipulate through any of your powers are also expanded to this power.
Embodiment
You no longer simply control your element, you embody it and may now freely shift your own body back and forth as you wish into your element the way you would with a Logia. If your chosen Devil fruit was a Logia, or a substance controlling fruit then the element or substance of your choice is added to your Elementalism's powers scope.