So this is everything we know so far along with some unsolved mysteries and suggestions...
HARDCORE EASTER EGG
There are 3 "tops" or "keepsakes" on the map that you place in the toy shop display and there are 3 enigma machines that correlate with the tops, 2 of which are in random windows. The blue enigma machine which correlates with the green top is found by blasting out of the bottom of the well and pressing the action button to knock down the metal sign right next to the toy shop display. After acquiring the enigma codes, you spin the tops and the cupboard that hides the record will slide open.
Once you've defended the tower, reset the switch in the laboratory and morgue to reveal a 3rd switch. Return to the main bunker, throw the final switch and shoot the coils that reveal themselves with Tesla Gun. Quickly grab a Brenner's head and shine both the safes in the morgue/lab halls to keep them open. Turn all 5 dials on both safes until they have a blue thumbprint to unlock them and acquire the stone-halves. Take both halves to the emperor's chamber and get the Red Talon from the front of Barbarossa's statue.
Spin the weather vane in the courtyard and shoot the small light that it points towards to reveal something. Once finished, go to the waterwheel and shoot the tesla coils that have rolled out from underneath. Use Red Talon & increased melee by the gramophone in pub to charge it (BEST DONE BEFORE ROUNDS 20+)
Use Brenner's head by Mystery Box location #2 to blow up a statue and reveal the 1st special tesla battery. Place the Hurricane battery in it's charger and use the S-Mine trap to kill lots of normal zombies till it's charged. This takes about 30 zombies to charge and the charger will start to glow green if you have the enemies you need. Once charged, take the battery to the Tesla Barrel forge and place it in the left slot, start defense process. After the hurricane barrel is forged, return to the tesla station and you will be able to forge your new tesla gun. The same process applies to all 4 batteries but the other 3 are harder to get than this one.
To get Midnight's battery, go to the lab and lead a bomber zombie up the small stairwell and have him blow up next to the large metal panel in order for the battery to fall out, now place this inside of the lab's electric trap. The trick here is to kill 2 brutes or "Wustlings" at the same time with 1 use of the electric trap. This will charge the battery halfway. After, that you must kill 3 brutes with 1 run of the trap, forge & defend in lab, assemble Midnight.
For Bloodthirst's battery, you will need the Tesla Gun which you use to shoot the flickering street light closest to Mystery Box #2, it will begin to spark, now shoot each sparking light, one after another with a regular gun and follow the trail of lights until you're in the morgue where the last light will drop the battery from the ceiling about 15 feet from the charger it goes to. You'll need to kill about 30-40 pests with the spike trap, make sure the charger is glowing before you trigger the trap for more accurate readings on this one, about 7 flybags will make it glow.
For Reaper's battery, you will need to lead a Wustling into the sewers, stand in front of the big metal panel, and shoot him enough to provoke a charge. Do not move out of the way, it's easist to let him strike you as it won't kill you on full health and this battery is best to get before your in the 20 rounds. I'm not 100% positive on this one but have successfully charged this battery at least 10 times in the past 2 weeks. You'll have to kill 2 bombers at once with 1 instance of the saw trap and then I believe another 2 with 1 saw trap trigger (though it may be 3)
After you have forged all 4 upgraded tesla variants, acquired the Casual VoG notes from the paintings and activated the Casual Voice of God, go back to the pub and listen to the gramophone to the learn the Hardcore Voice of God that is played in morse code, The red light on the record player's side will indicate that it is about to play the first note and every note is learned by listening to the subsequent amount of clicks on each note followed by a space between each note. Return to Emperor's chamber and sound the Hardcore notes
Now, DON'T SHOOT THE ORB JUST YET! Use all 4 of the upgraded tesla rifles to shoot the chandelier located above Barbarossa's hilt. You should see a swirl of energy within the center if done correctly (aim for the candles). This can be done with teammates or even done solo, you will just have to run back and swap between all 4 teslas. Some guy didn't know that the casual notes had to be sounded before the hardcore so he left the game and I had to do all of this shit and fight the Panzermorder alone
And that's basically the whole hardcore easter egg, I won't spoil the ending.
MONEY BOWL EASTER EGG
There are 4 special bowls on the ground in certain parts of The Final Reich. One is in the morgue, containing dollar bills. The second is at the front of the Army Flatbed in Village Square. Bowl #3 is down in the courtyard on the frontside of the building that the large statue lined with liquor bottles is behind. (Where the Yellow EM spawns sometimes) The last bowl is in the pub behind a table next to the extra weapon damage blitz machine. Put 250 jolts in each bowl to see an animation of money swirl out of them like a tornado. Once you've dropped jolts into all 4 you will be able to find a new gun in the Mystery Box called "The Classic" which is a tribute to Treyarch's original PPsh from W@W and is probably the strongest gun to use maybe beside's "Roland's Count" or "Good Enough" It has the highest fire rate in the game, basically like a PPsh but doubled, way faster than even the Waffe 28.
UNSOLVED MYSTERIES AND POTENTIAL LEADS
• There's alot of open vents in the bunker that you can throw grenades into.
• Why there is a Jack-in-the-Box crest underneath the weather vane in the courtyard?
• There are also crests upstairs in the toyshop as well as a mysterious white frame at the right as you enter?
• Bust out the window next to the first valve and there is a flower crest on the fireplace by the wheelchair.
• The weather vane at the tower's peak along with the 4 lightning rods and the tower's 2 unlit rooms?
• The weather vane and eagle's crest in the spawn as well as the tower's eagle crest?
• The 7 or 8 chimneys that can be blown off of the rooftops, perhaps in a specific order?
• The many roman numeral markings, most of the outside ones, when stood at, give a clear shot at the rods?
• A line of 3 clocks in Straub's office and another 3 in the upstairs room behind the barrel forge?
• There are clocks hidden in windows on the map that correlate with the clocks mentioned above.
• 2 grandfather clocks on the map which correlate with the clock tower and street clocks.
• Why do the street clocks blank themselves white for a limited time when hit with sticky grenades?
• Bird cage in Straub's office? The battery names do happen to be named after birds.
• When someone threw a Jack-in-the-Box on the chair in Straub's office, it just kept spinning?
• Oberflache grids that are found in every indoor section of The Final Reich?
• There are multiple vents within the bunker that you can throw grenades into
• The metal panel on the upper-outer face of the building next to the bunker. (Panzermorder?)
• Strange polygonal figure next to the clocks in Straub's lab that still hasn't been patched?
• An easter egg was said to involve the wheelchairs but no one ever found this out.
• 3 gold-laced oval portraits of a woman that can be found throughout the map.
• I found a strange black panel in the hallway behind the Tesla Core forge that can be blown off.
• 2 known music sheets hidden in bookpiles that can't be picked up but are legibly readable.
• Several small toy figures hidden throughout the map as well as countless liquor bottles.
• Also worth a note, maybe, the 2 buck heads and the record player in the spawn window.
• The same sacrificial hoist from The Darkest Shore can be found in the morgue.
• Why does the gate in the morgue look so prominent? Why does it say "Emergency Exit"?
