Deal with the (Dream) Devil

Sprig can't deny it. He misses Anne. After years of wondering, he feels like he won't see her again...and maybe that's fine...until a mysterious entity gives him a deal. Just when you think all is lost, someone(or something) comes up with a bargain. (Gravity Falls/Amphibia Crossover. Slowburn Anne/Human!Sprig. Rated for Language and Suggestive Themes)