There are 12 skills tied to this achievement. They are shown in the skill wheel accessed with LT:
Seven are story related acquisitions and five must be purchased from Opher in Wellspring Glades.
Spirit Edge, Regenerate, Spirit Arc, Flap, Light Burst, Flash, and Launch are found or given through story progression. Launch is the last of these that you will acquire and Regenerate is the only one of these that you don't actually need to in order to progress (but it's all but impossible to miss).
Sentry, Spirit Star, Blaze, Spirit Smash, and Spike are sold by Opher for 400 Spirit Light (on Normal difficulty- the price is halved on Easy and doubled on Hard).