There are 3 builds in this game.
1.Balanced build: You make sure to have enough HP on your heroes so they can survive a few hits from enemies, while at the same time your heroes kill them with a single blow. Doing this requires you to level up anything attack and health related. With this build you can farm up at a normal pace after a prestige. Kill speed with 4 balanced heroes is about 65-70 kills per minute.
2.Guardian build: You let the guardian do all the work for you. This requires a clicker (which is allowed). You only have to level up anything attack related. This means wrists, relics and all main attributes too, as they benefit guardians too. Guardian build only works temporarily as heroes can and will be more buffed throughout the game. Out of the 3 builds, guardian build is the quickest way to farm up after a prestige. Even more so when using the dragon. When the guardian is much stronger than the heroes, to the point where heroes don’t do any damage at all. You basically get no to very little gold using gold items.
3.Glass cannon build: You only focus on attack. Your heroes don’t have any health or armor. Your heroes die when they get hit, but they kill the enemies too. As you only have to focus on attack and not on HP, attack is higher compared to a balanced build, allowing you to farm higher stages. After a prestige, when you farm up, the first 85-90% of the stages will go at a normal pace. The last 10-15% of stages will be painfully slow, that’s when the heroes starts dying. Kill speed with 4 glass cannon heroes is about 30-35 kills per minute. You also get a ton of gold using gold items, as HP or heroes alive does not affect the rewards of gold items. It only uses DPS to calculate the reward.
4.Going full retard build: You only focus on armor, and ignore the rest.