 Bill Cipher isn't an SCP, but if it was, how would the SCP Foundation contain it? Ah, I love having options. We have got five. Count them. Five different containment procedures for our favorite one-eyed monster. What do you mean it's not your favorite one-eyed monster? Oh, shut up! Ketter duty one week. God. Okay, so first, the Zodiac containment spell. It's a classic. It didn't work in the show because of sibling rivalry, but with proper persuasion, we can knock this one out by the books. In Scenario 2, Bill Cipher is lured to a location, and the thaumaturgical spell used by the Pines family to protect the mystery shack, the one including unicorn hair as a component, is used to seal Billy Boy into a single location. We build our remote containment site around that. Now, say we can't get access to unicorn hair for some reason, like Marshall Carter in Dark decided not to share theirs this time, a lousy jerks. In that case, we can still evacuate the town of Gravity Falls, Oregon, and leave Bill with all his weird-mageddon, well, weirdness, locked inside the protective barrier of Gravity Falls. Town-wide isolation is better than nothing. But okay, I know what you're really here for. No unicorn hair, the town barrier nullified. What do we do if a free Bill Cipher is ready to tear up everything? The same way they did it in the show, mostly. See, our foundation is knowledgeable about multiple realities, different dimensions, and all manner of things outside the bounds of our perception. Bill is always looking for the next big place to party, so I say we give it to him. Send Dr. Bright out there with a promise of some sort of enticing knowledge, convince Bill into Bright's mind, and immediately put Dr. Bright into a coma. Remove the amulet and place it on another D-class to bring Bright back and put the old comatose body into a stasis cell. Presto, freeze-dried Bill Cipher. And of course, while we do not like destroying anomalies, we do what we have to do to maintain normalcy. So if none of the above plans worked, it is time for Ford's quantum destabilizer, held by someone who won't miss.