Premium Resonance Potion Development Materials Provides 20,000 Resonator EXP.

A potion that can significantly enhance the user's Frequency perception. Its formula is locked within a vault with the highest security. Rumor has it the inventor of this potion is a powerful Resonator in their own right, and their hope is to groom a successor capable of surpassing their achievements.
Sources
Quests
Huanglong Exploration
Simulation Training
Gladiator's Portrait