Only then will you be able to level up your alt characters significantly faster — allowing you to get more Class Grade rewards (specifically Diamonds) quicker.
How To Farm Diamonds
Diamonds are among the rarest resources in NNK:CW, and here are the only two methods you can use to farm them.
Method #1: Claim Class Grade Rewards (Best For Early Game)
Class Grade rewards can be claimed once your character reaches a certain level: Using your main character, I recommend you play from the early stages of the game all the way to Level 60, where you can claim your first batch of 1,000 Diamonds. From there, feel free to level up your alt characters to Level 40, so you can proceed to the second method of farming Diamonds more smoothly.
Method #2: Create Alts For More Class Grade Rewards (Best For Late Game)
After leveling your alt characters to Level 40, you may now raise your main character’s level to around Level 70 – Level 75. Your alts will be able to take advantage of an EXP Bonus buff if you do this, and you’ll be able to level all of them up to Level 60 fairly quickly if you AFK farm consistently enough. Once you reach Level 60 with all four of your alt characters, you’ll receive 4,000 Diamonds in total from cumulative Class Grade Rewards. You can do this cycle continuously if you want to farm Diamonds completely F2P — even around Level 100 and above!
What To Spend Diamonds On
Here’s a table of items in the Shop that you should consider spending your hard-earned Diamonds on — ranked according to their cost-effectiveness. When it comes to pure cost-effectiveness, you can’t go wrong with purchasing one Energy Drink per day, or at least thrice every week. The only shop items that come close to the cost-to-benefit ratio that Energy Drinks have are the Rebate Bundles which only come around once in a while. Keep an eye out for them! Dark Magic Crystals and Equipment Enhancement Stones are also great pickups — especially if you’re already in or near the late game. AI Mode Time is a decent occasional pickup if you want more AFK farming rewards from a certain monster mob. TIP: Never spend Diamonds on Equipment, Familiar, and Costume Summoning Banners if you’re completely F2P. Just farm Summoning Tickets! You should also think twice before using Diamonds on in-game refreshes, or on instant revives after being killed in tough fights.