“Mercenaries” is a new feature coming in patch 1.21. It can be unlocked after completing stage 6-40 and allows you to “hire” heroes from players on your friends list.
In order to hire specific heroes you must send a request to the player for them. They can then choose to either accept or ignore it. There’s also an “Auto Lend” feature that will automatically accept all requests.
Heroes of the same name can only be lent to one friend at a time, for a maximum duration of one week.
Only heroes that are Legendary tier or higher can be hired, and they can only be used in the King’s Tower an Campaign stages.
If a battle is won with the mercenary, the amount of times it can be used will be reduced.
Players can hire up to a maximum of 3 mercenary heroes and send a maximum of 5 hero hiring requests at the same time.
The attack rating of hired heroes will depend both yours and your friends attack rating.
If a player on your friends list has been offline for 7 days or more, you can’t hire their heroes.
Esperia is a land full of surprises but also crises. If you want to travel or take adventure here, there are two things necessary, courage and companionship.
Courage allows you to embark on an adventure without hesitation and support you through the most difficult times. When the courage cannot solve the problem, it is a wise choice to hire a reliable adventure partner.
Guide to Adventure in Esperia, Explorer Gretel Hawk