As One Glastrier

As One Glastrier is a unique signature ability exclusive to Calyrex in its Ice Rider form, representing the fusion of two distinct Pokemon into one powerful entity. This ability combines the effects of Unnerve and Chilling Neigh, giving Calyrex access to both mechanics simultaneously. The Unnerve component prevents opposing Pokemon from consuming their held Berries during battle, eliminating their ability to recover HP, cure status conditions, or activate other Berry-based effects. Meanwhile, the Chilling Neigh component provides an Attack boost whenever Calyrex knocks out an opposing Pokemon, making it progressively more dangerous as the battle continues.

The dual nature of this ability makes Ice Rider Calyrex a formidable threat in competitive play. The Unnerve effect disrupts common defensive strategies that rely on Berries like Sitrus Berry for recovery or Lum Berry for status cure, while the Attack boosting component rewards aggressive play. Each knockout further enhances Calyrex's already impressive physical attacking power, potentially allowing it to sweep through entire teams once it gains momentum.

This ability perfectly encapsulates the fusion concept behind Calyrex's alternate forms, mechanically representing how the legendary Pokemon retains its own psychic abilities while gaining the ice horse's battle-hungry nature. The combination creates a unique strategic dynamic where disrupting the opponent's healing options pairs with an escalating offensive threat.