Viewing the original animation, I felt the visual feedback was smooth but lacked the visceral impact necessary for a core progression mechanic. To fix this, I engineered a sound effect grounded in the concept of tension and release: a rapid, rising synthesizer swell builds immediate anticipation to match the visual charge-up, which then snaps into a crisp, resonant burst. This heavy, punchy release provides the auditory weight needed to make spending hard-earned XP feel like a genuine achievement rather than a simple UI selection. Since these unlocks are designed to be infrequent milestones rather than repetitive inputs, I felt comfortable pushing the intensity of the "thud" and the magical decay to ensure that every time a player commits to a skill, they are rewarded with a powerful, gratifying sense of permanence.