His frown deepens upon hearing the part about the missing sun. Taking a 'big hit' had seemed reasonable, but for the sun to no longer rise? There's only one explanation for that.

"...so. The Eternal Night will set in, then." He leans back, the wheels already turning quickly in his head. "Sounds like we'll need to make sure that the lights all stay on until our King ascends to his throne."

Which means more recruits to train and ready for the inevitable retaking of Insomnia. Cor's got his work cut out for him already, but if it's for the good of all Eos...