Underfalls: A Gravity Falls/ Undertale Crossover

"Dipper, there is one last thing to prevent Bill's reign of terror for good. You must climb to Mt. Ebbot, not far from here, and retrieve some inter-dimensional travel-block. It will prevent Bill from ever crossing into our realm, and taking over our world." "Ok Great Uncle Ford. I'm on it-" "Oh and Dipper?" "Yes Grea...