The Portal Emerges

This is a revised version of @Julianna_isme's "The Thea Sisters Travel Through Dimensions!". All of the characters belong to their respective owners. The Thea Stilton characters belong to Elisabetta Dami; Adventure Time characters belong to Pendleton Ward; Steven Universe characters belong to Rebecca Sugar; and the Gravity Falls characters belong to... (actually I can't remember who created Gravity Falls, anyway, moving on!) Cringe bomb warning, by the way!