This guide is for when and how to try to do this, without a doubt, most difficult late game achievement.

It took me bit less than 24hrs (including 8 hrs sleep with game left open, but I'm sure with some luck is doable in as short as 8-10 hours) to do it and it requires quite active style of play focusing on shooting down every firefly there is so I suggest, if you want to do it in same time frame, start it when you can spent good few ( more than a few ;) ) hours on active play or be ready to spent on it significantly more time if you can spent less time on active play in one sitting. Passive will get you nowhere here due to to low gold/sec income as there is no buildings allowed to achieve it.

so...

Not quite sure when is best time to try to get it but I will tell you what my stats looks like before this attempt so you can judge if you ready for it or not quite yet:

Kimono of Legends 600%
Katana of Legends 105%
Kabuto of Legends 30%

Achievements 645

AS – all and Tiger lvl2 and Dragon lvl1

Ascend Bonus - 30.29e09%

Elements – 147/145/108 respectively

MU – all

Pets - Bunny – 12, Panda - 8, Raven – 12 - I'm sure one will find better team here but I just used what I got at the time with best bonuses I could master.

Try to get all bonuses to gold/s from all sources as high as you can, as you are cut off from having any buildings, any extra bonus to gold/s is vital to shorten your pain to win this.

Stating the obvious you only buy research upgrades here and you should get tier 6 completed instantly (or lets say in less than 10sec, for argument sake)

within first hour of play you should have at least 80% of each 7 tier upgrade (anything should cost more than 200e36 gold)

You got to shoot every Firefly there is to maximise income and shorten the time to achieve it – it will get you nowhere without this approach, you need all multipliers and bonuses from them, better yet few at the same time, so you can boost your gold/s as high as you can (best combo is good % to coin value – around 300% - good multiplier – x7 will do and if lucky firefly storm with shuriken vortex can give you 1e39 in seconds) if you manage to get lucky ( I did just once) and get The Big One (x50) instead x3-7 in that combo it can do few hours of gold in seconds if combined with samurai frenzy or firefly storm

While doing Tier 7 focus on Pasture, Cloak and Bamboo first as this will give biggest gold/s boost so you can get the rest easier.

After 4-6 hour session you should get tier 7 to the stage when you should have all upgrades bought up leaving just last three at 1e39 gold in price. Rest of run is purely up to luck with good fireflies combo.

Lastly to help you calculate how far you are now and how much more you need to get you to finish line:

Tier 7 upgrades are done at

Defensive Offence – 6 ( buy 12 times)
Pasture Fields – 200% (buy 50 times)
Ruby extracting – 0.3% (buy 30 times)
Hobnailed Boots - 2 (buy 2 times)
Cloak of Legends – 0.1% (buy 20 times)
Bullion Production – 12.5% (buy 50 times)
Bamboo Harvesting – 250% (buy 50 times) this will be most expensive one to last one costing 7.99e39

I Think ideal is to get around 30e27 gold/s after few minutes of play, 50e27 mid stage and 80-100e27 late stage, to do it within 24hrs without a problem (this topped with multiplayers from Fireflies will be enough to have decent progress here)

you will need total of approx 80e39 gold to get it done.

Done on v5.0.9

Good Luck!!!