Chapter 679: Chapter 679: "Formation" Upgrade

The power of the Book of Fusion lies in empowering the primary skill set without any dependency on the compatibility of fuelling secondary skills. It could even promote skills with properties totally against each other.

Theoretically, Song Jian could merge all his skills to generate a full-level skill. But doing so without identifying the quality of the primary skill would only weaken him.

"Set 'Array Formation' as the primary skill!" Song Jian decisively dragged the skill into the primary skill slot. He then scanned through other skills and finally selected "Magic Rune Inscription" and "Magic Rune Array" to be consumed.

"Magic Rune Inscription" was only a third-level skill, but Song Jian had already promoted "Magic Rune Array" to seventh level. Both skills could supply a lot of proficiency for the promotion of "Array Formation".

Song Jian was immediately greeted by a system notification after dragging the two skills into the secondary skill slots: