In Amberser's adventurous life as a mage, there weren't many things he rode. After all, for any special terrains, he'd simply fly over them with a Flight Spell, and for long-distance travel, he would just ride a horse.
So riding a Black Panther was a first for him, and the experience was far from pleasant.
When Katherine rode the Black Panther, her body undulated in perfect sync with the panther's running rhythm, as if she were about to merge into one with the beast.
Amberser, on the other hand, felt as if his bones were about to be shaken apart. If it weren't for his ability to leap into the air and spin around seven and a half times on the spot, he probably would've been thrown off.
It was only later that Amberser learned riding skills were not included in the ranger heritage; Katherine had practiced on her own afterwards.