This matchup is what Bill vs Sans wishes to be tbh

Two enigmatic antagonists with a charming and fun but crazy and unhinged personality known for making deals with people for things that may or may not be good for them (but definitely good for our fighters) to get what they want, with one of these victims being the kid protagonist(s) of their story (Kris/Mabel and Dipper). They actually manage to succeed in getting what they want through this and achieve greater power, obtaining new forms (Bill ascending into a 3D form and beginning Weirdmaggedon and Spamton being granted his NEO form), although their victory is short-lived thanks to said kid protagonists (Bill being defeated via being wiped from existence and thus ending Weirdmaggedon, and Spamton having his strings cut or just generally beaten up and in Snowgrave being frozen to death). Both at first didn't seem to be much, simply appearing as a minor antagonist, but they become bigger influences as the story goes, acting as the final threat (specifically in Snowgrave, and yes I am aware Spamton is only a Chapter two boss but shut up-). Again, if you count Snowgrave, both wish to rule over the world they inhabit with the only obstacle being the kid protagonist(s). Both resemble a certain thing in a way (Bill resembling the Eye of Providence and, as alluded to by Swatch, Spamton resembles him, though he more-so is trying to personify him). Both also... *sigh* act as the Tumblr Sexyman of their series...