No matter how far you are into the game, you will never be rich enough to purchase everything you need. Upgrades alone are expensive, and you constantly have to purchase items if you use units that need them, like Medina. It’s all worth it at the end, of course, but that still doesn’t change the fact that you need a lot of coin.
If you want to farm coins, the best Mental Mock Battle stage to spam is Close Quarters Combat (Lv. 10). It will reward you with 2,000 coins—not to mention the resources that you gain, which you can sell for 70 coins each. The map is flat, and the enemies are few and weak.
Later on, you’ll unlock The Chaos of Battle (Lv. 18). The reward is 4,000 coins and a lot of treasure chests can be opened, which contain large pellets, ranged pellets, and ranged stones. Spoils are also scattered throughout the area.
However, the Abandoned Village is an annoying map to navigate. Not only is it big, but it has tall cliffs and its enemies are scattered. Some enemies inflict fury and immobility, wasting turns. It’s technically a good place to farm coins but only when you’re strong enough to one-shot everyone in the vicinity. The stage is just not time efficient otherwise.
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