Okay so here is what I believe the best way to get (essentially) infinity gold and advance quickly.
A warning beforehand: you need to prestige about every 200 levels past your current max or you may get teapot-ed. For example: if your highest prestige is at 650, prestige when you are at most at 850. Not sure why, but I'm assuming increasing your stage too fast flags your account and then leads to a ban.
Search for your main hero level (under the first tab with a sword) as an Xor Encrypted. (takes a long time for the first few searches)
Increase level and refine your search until you are left with 1 result. (may take 20+ searches)
Once you have the address, select it. Then long press down on the address and select "go to the address."
Select only the address it sent you to and click on it to bring up a new screen.
Select Qword and change the value to -999999999 (that negative with 9 nines).
Go back into the game and change the buy amount to "buy max" (should change the upgrade cost of your main hero to "***"
Upgrade your main hero (the level will say its something like -98792387461238947097, and that is okay)
You will now have 100.00dd gold.
Go back into game guardian and make sure only the edited address is selected.
On the top bar, there should be a symbol that looks like a back arrow or U-turn type symbol, press it.
Again select Qword and then hit yes. This reverts the value back to its original and lets you keep the gold without changing any of the games information permanently
Back in the game, change buy max to buy 100 and upgrade your main hero to 600. Use the rest of your gold to upgrade whatever you want.
Caution: Giving your heroes high levels or upgrading high level heroes allows you to advance through stages very quickly. Like I said above, if you prestige at a stage more than 200 above your current max, you risk getting banned (you will most definitely get banned based on my experience), so make sure you pay attention to what stage you are on.
Sorry for the long explanation, just wanted everything to be as clear as possible.
