Light wore an unbelieving expression while staring at Kyran, after witnessing him unleash a powerful range Light magic attack.
Light's reaction is justified.
If Light was using magic arrays, Kyran's sudden use of Light magic attack could be justified. Any mage could summon other magic as long as they knew that magic's rune system. If that mage also hadh in-depth knowledge in Runes, the power output of their attack would be better. However, it was still uncomparable to mages with innate magic unleashing an attack.
Light's understanding of this fact was shattered by Kyran with one simple move.
Because the strength of Kyran's Light magic attack is not inferior to Light's— an impossible feat especially when Kyran possessed Void magic, which was considered too perverse but limits its user from using other magic.
It made Light reassessed Kyran's worth to their faction's objective.