my idea of what they'd be like is ever-changing --- so unless they're a changeling sort it won't work
when I think of what my OC would be like, all that comes to mind is some esoteric force of nature that also happens to have an ego
although in terms of visuals, guess I'd say the true representation would be like, a faded silhouette with radiant eyes that leave a trail behind them, embers of the void constantly falling off them