By this time Bill has forgotten everything about the vision except an armageddon.
3 months before...
Bill had just been messing around with people for a while. Created the worst nightmare imaginable for Preston Northwest, Entered Tyler's dreams and scarred him by telling him that a puma and a panther are the same thing. But he didn't know that Violet told a few people that he was around. Hell, She told everyone she knew. Which meant she told Nadia.
Turned out before Violet told her Mom. The entire Multiverse had been celebrating. Now half of the multiverse knew since Nadia is always traveling through dimensions still hoping to find Ford's home dimension. If Bill had any chance of getting rid of the Pines family once and for all he had to trick someone close to Nadia.
Someone with a well-known fear. He needed to trick someone...square. Of course he couldn't do it now. That would be a death wish. He only wanted to kill the Pines family and their friends. Plus killing an entire mob would draw too much attention.
He needed to wait. He could still hop to any dimension he wanted. He needed a dimension he could stay hidden in. He knew the perfect place. Dimension 29.5/.
A dimension inhabited by nobody since The Mutant War. If he stayed there to formulate a plan he could capture Tad, Destroy the Pines, and bring something even worse to Weirdmageddon to Gravity Falls.
So Bill Cipher formulated a plan. To even get Tad he needed a device that could only be found in Dimension 105.8. He needed The Decider. 350 years ago it was used to decide if you were to be good or evil. Used a long time after Bill was created. But after 37 years of using it an evil group called the A.A.S.G. tampered with it and made it so it turned everyone evil.
People soon discovered this and all the good people buried this in a safe place where no one would ever find it. Bill knew exactly where it was though and he knew what his elixir did to anyone who had tasted it. So with his elixir, a more tampered Decider, and a bit of hypnosis liquid he could take Tad as his minion. Still Bill had to wait a bit or he'd be sent back to Dimension Svoo.
"This may take a bit" Bill said to himself. He summoned some elixir and immediatly drank the whole thing through his mouth eye thing. Bill needed time for his sudden resurrection to die down. So he waited. For a while.
Which means the next chapter can focus on Nadia and the others and what they're up to. Yay! Please review! And favorite and all that good stuff.