Except collecting gold and diamonds, you can also be assigned to gather up the artifacts, which you can open at the beginning at level 80 of your heroes in that you will have to get relics first.
Later on, if you do not like the artifact that you get at that point, you can break it down for a relic that you can do with diamonds.
From there, every time you level up your warriors, you will be able to earn one or more relics when you beat bosses.
Also, you will be able to get relics that you can do by unlocking Prestige.
Early on, you should upgrade your own warrior up to level 600 then you will notice Prestige to be come up in the abilities menu.
After unlocking Prestige, you will restart the game
Anyway, you will have the ability to get relics and artifacts.
In related to the prestige, you can do it more than once after upgrading your warrior taps to level 600 in which make sure to keep your gems every time that you do this.
On the other side, if you get prestige, you will also be rewarded with a relic bonus for the amount of levels that you have beaten
Moreover, it is based on the number of team members that you have, then you will collect an extra bonus if you can unlock every single team member in the game.
The main point is by using all of that prestige that you earn from doing this, you can collect those artifacts
For further, those artifacts will be more expensive if you upgrade them with relics.
When upgrading artifacts for the first time, it will require only two relics, then it will require more relics for the next upgrades.
In the way of getting more relics in this game, you can break down an artifact that has been upgraded already.
It is caused by, if you have already upgraded an artifact, you will sometimes keep it around or you choose to use it.
You will often get a relic from the treasure chests that the angels are carrying.
Generally, you will have to struggle defeating high level bosses in this game in order to earn more relics form them.
Furthermore, making prestige will go by faster than the last time due to all of the boosts afforded to you by the artifacts every time.
Once the artifacts pile up, you will have the damage boosts and the gold boosts in faster ones in which it will make it a much quicker job to earn relics along the game.