The largest runes read Sunny and Sunless
Somewhat spoiler(?) for vol 7 for the rest of the runes
||The two outer frames and the top left corner read ‘ Careful what you wish for’ a reference to the floating wood Sunny found at the beginning of the river of time. The next two inner frames repeat the word ‘wish’ as does the repeated runes u see across the whole art. And the only word on the last inner frame reads ‘help’ it’s very hard to see||.
The runes are Dovazul , the Dovakiin language of Skyrim <:anime_dude:1003962839159017512>

||It’s heavily implied that Sunny is turning into the mad prince the further you look into the depth of his character (the frames)||