Idle Heroes have a myriad of Artifacts where each Artifact comes with its own unique stats and abilities. There is a grading of Artifacts done in the following manner:
Orange>Red>Green>Purple>Yellow>Blue
Artifacts which possess the same value of engulfing have the same cost for upgrading themselves. When there is a need to use a greater number of engulfing points, one needs to upgrade the Artifacts, which then converts all the redundant engulf points into Afterglows. 1 Afterglow=10 engulf points. However, you cannot upgrade or disassemble an Afterglow.
Orange Artifacts
This is the best Artifact among all the Artifacts. They are generally not found easily. Since they are a rare category, their cost is high.
Engulf Value:5400 Pts
Upgrade Cost:5400 Pts (Per)
Orange Artifacts have two genres
(1)Normal
(2)Exclusive
Exclusive Orange Artifacts
These Artifacts are more brawny as compared to the normal ones. They also provide some additional properties for a modicum amount of charge.
Red Artifacts
They have quite sturdy properties. They are however weaker than orange Artifacts.
Engulf value:2400 Pts
Upgrade cost:2880 Pts
Red Exclusive Artifacts
These are also considered to be stronger than the ordinary Artifacts as they provide extra properties for a little amount of money.
Green Artifacts
They are considered to be the best choice for novice players. They provide good quality stats. Green Artifacts can be obtained from event campaigns from 13-1 to 15-10.
Engulf value:650 Pts
Upgrade Cost:1440 Pts
Purple Artifacts
They are although good for novices yet not as efficient as the green ones. They can be obtained through Events, Casino, and Campaigns from 10-1 to 12-10.
Engulf value:150 Pts
Upgrade Cost:580 Pts
Yellow Artifacts
They are also good for beginners, but their loophole is that they do not have great stats but are better than Blue Artifacts.
Engulf Value:40 Pts
Upgrade Cost:190 Pts
Blue Artifacts
They are considered to be the weakest among all Artifacts. They are easy to obtain at the beginning of the game. They need to be upgraded to Max very fast.