In EO, the loyalty decides whether you can summone your eudemon or combine with it.
When the loyalty is below 50, you cannot summon it.
When the loyalty is below 80, its level up will decrease its quality.
When the loyalty is below 100, you cannot combine with it, and it will not get a talent reward.
Only when the loyalty is 120+, you can login to the Eudemon Profile and use some advanced combine skills and the star light effect will appear.
When the loyalty is 150+, if the player's HP is low, the player's damage will be converted to the eudemon, to show its loyalty.
When will the loyalty increase or decrease?
Increase:
1. If you keep the eudemon with you
2. Summon it in fight; its level up will increase its loyalty.
Decrease:
1. If the eudemon is killed or is dead.
2. Exchange it with others, the exchange will cause a decrease in loyalty.