Robotnik is a half-elf
Stone is a deer person (deerfolk)
Robotnik has a mission that can only be completed by traveling to a different dimension that exists outside of the standard material plane. He finds a fey crossing in a reflective pool that seemed to refract light differently than the surrounding waters. After diving in headfirst, he finds himself in a pond in the middle of the feywild.
Robotnik emerges from under the surface, gasping for breath and rubbing the water from his eyes. Compared to the mystical silence of the forest he's in, Ivo's movements are incredibly loud. It's not until he makes eye contact with a creature that he stops what he's doing and opts to quiet down.
There, standing in front of him on the edge of the pond is a sunkissed man with graceful deer legs. His human torso and arms are covered in soft body hair that transitions into fur once it reaches his hips. He has these brilliant antlers covered in blooming flowers, vines, and other various foliage. His eyes are ink black, but shimmer as if there's glitter in them.
They hold each other's gaze for what feels like eternity. Neither of them move or speak until the deerfolk's ears twitch with curiosity and uncertainty. Suddenly, Robotnik blurts out,
"I'm Ivo."
He doesn't know why he bothers to introduce himself. That's not why he's here; it has nothing to do with the task at hand. Yet, he felt compelled to do so, drawn in by some imaginary (or perhaps real and just unseen) force that made him want to befriend this being.
The deerfolk seems to take a moment to contemplate the sudden turn of events, before he smiles. His smile pricks Robotnik's heart in a way he didn't know was possible. He introduces himself with one word,
"Aban."
Then, he turns away from Robotnik and prances off into the thick brush of trees that was behind him. Robotnik is left in awe and breathless, still standing in the middle of a body of water.