Area 51
| Lv1 Mythic Emblem | |
|---|---|
| Effect | First stage gains
Second stage gains Third stage gains Boss stage gains |
| Boss | Maniac, Humanity's Last Hope |
| Sigil | Lv1 "Cleanse" |
| Divine |  Glasses |
| Cost |  10 Tokens 10 Star 10 Cactus 10 Shard |
Area 51 is a Beyond mode Emblem.
Strategy
I used the 
Auramancer Mastery for a balance of souls, defense, and stage power reduction. 
Marksman Mastery is an obvious choice to keep a chain going to kill living creatures more easily with the Lawless mod, and would be especially good in the boss stage (unless the lawless mod can kill the boss, which I don't believe is true). Really, the stage mods are not too intense, so any mastery you like is probably good. I used the Pathfinder chest, but again any chest you like is probably fine.
The main thing to note is that the boss has a special rule where killing all strangers wins the stage, but solving the stage normally makes you lose. You can use the Lawless mod to help with this, or if you have good life/defense or are a Marksman you can make mistakes and the boss will kill strangers. I had luckily picked up a 
Fire Bomb in the previous item shop and had a small open, so that took care of it for me. Bringing a 
Cudgel in your heirloom slot might not be a bad strategy.
Remember you can make long chains by incompletely chording the same cell multiple times (e.g. if there is a known monster next to a 1 and 4 empty cells, you can flag 3 of the cells, chord, unflag a cell, chord again, and so on).
Drop Condition
When you use 
Candy, 
Fake Candy, or 
Big Candy to fully feed a stranger, there is a moderate chance (around 1/30) you will obtain Area 51. Fully feeding a stranger requires 10 candy/fake candy or 1 big candy. You must also have completed the Halloween questline, or be on the last one. Having Glasses in your inventory boosts the drop rate to 1/3.
This is fairly easy to farm during Halloween with the use of Spookers, To get enough candy the best way by far is to get a 
Book of Ghosts- I recommend crafting this and starting with it, but you could also just restart the quest until you get it early from a Spooker. With the book, getting Candy and ideally Big Candy buffs online should be easy. I think 2 Book of Ghost with a couple candy buffs active or 1 book with a lot of candy buffs or big candy active should be sufficient to fully sustain candy and feed all strangers.
To get strangers you can use the 
Detective Mastery, the Friendly special chest, and favorite items like 
Nomad Medal or 
Handbell. I find that with a medal favorited there is a very high chance to get that medal in the first shop.
Notes
This emblem is only obtainable during the Halloween event, because it requires the Halloween questline to be completed. Completing it during a previous event does not count.