Kyran did not hesitate to enter the range of the enemy's multi-casted spells. Doing so was not to say he underestimated the level of magic the enemy had used because they were all cast by a peak Sovereign or probably even a High Sovereign. The reason Kyran was not worried about being affected by the spells had more to do with the nature of his Void magic.
Before Shaiha took over Kyran's central core, his Void core would proactively circulate his Void magic energy. Thus, he was immune to status spells and other harmful magic attacks that aimed to affect his body.
Yet, when Shaiha assumed control, a sacrifice was made. In order to ensure Kyran's safety from those who could recognize the Void core's energy or magic signature, the Void core's circulation was regulated. This decision, while reducing Kyran's immunity to unseen and harmful magic attacks, allowed Shaiha to conceal his aura and presence better.
