So, Rhydar are pretty interesting creatures. Post-apocalypse radiation and magical energy (long story short, this world was apocalyzed-rendered apocalyptic-by another world's inhabitants-magical creatures-invading it, which led to humanity deploying nukes and other highly destructive forms of weaponry in order to save themselves from their supernaturally powerful foes) turned them from regular rhinos into blind, violent yet highly efficient predators, capable of compacting and altering the flow of air to pull off devastating sonic attacks.
However, despite all this, I've imagined Rhydar as being symbiotic, like regular rhinos. How could this be possible?
Why I'm Asking: If Rhydar can echolocate and have a strong sense of smell, and they're naturally violent and aggressive creatures, it would seem that they wouldn't need or be able to form symbiotic relationships. Yet, I've imagined Rhydar as being able to benefit from and bond with other monsters, from bird-like entities (Needki, a mutant Kiwi Bird, or Bagooska, a mutant goose) to intelligent, humanoid monsters like Drakeneko or Elvaris.
This bond is so critical that without one, Rhydar cannot evolve (mutate into a higher form) without bonding to another monster, which rides on it and helps guide it through life, while also having a heavy influence upon Rhydar's evolution. This means that somehow, despite the above, Rhydar can not only bond with other species and benefit from the bond but bond so deeply that their form changes to reflect their rider! Thus, this question is critical to explaining how Rhydar can evolve into Rhydrage (and yes, the evolution name is based off of the phrase 'road rage =)).