Daiyousei looks like Nanoha here..

Daiyousei: Cirno...let's cool off that head of yours. *cue curb-stomp battle*

Dayousei: You are the chaser!

Daiyousei said:
"I want YOU, to join the fairy-uprising!"

FangPanzer is correct.

Pixiv title: チルノちゃん…少し…頭冷やそうか… (Cirno-chan...shall I...cool your head a little?)