You can awaken a Saint’s Seventh Sense by spending Awakening materials. Doing so increases its attributes and unlocks its Awakening Skill. The cost of Awakening is different for Saints of different quality. Awakening materials can be gained from material instance—Dimensional Space. Advanced Awakening materials can be created by crafting low-level materials. Awakening materials can also be bought in the shop.
Tap on the Awakening button in the Functions menu on the left-hand side. Once you have all of the materials, tap the button in the bottom-right corner to Awaken your Saint. Awakening a Saint will unlock its powerful Seventh Sense Skill.