Level 5 toe ring skill imbuing both Extra Steady Balance and Walk on Air.
Physical Balance is the third of the level-5 skills imbued by the Enchanted Toe Ring of the Well-Balanced, representing balance in the physical core. At level five it grants both the Extra Steady Balance skill and the Walk on Air skill.
When Carl read the description in chapter 10, the ring listed Walk on Air as "already obtained," which made no sense to him until he remembered it was Li Jun's skill — and that Shi Maria had warned he might gain some of Li Jun's abilities after eating his eye. The realization left him nauseous and guilty.
The toe ring skill that inadvertently confirmed Carl absorbed Li Jun's abilities.