Hero Training Edit
The maximum level that a hero can reach is capped though.
Basic Training increases the hero's level cap by 10, up to 200.
Master Training allows your hero to be trained by your best hero. This option is only available when you have a stronger hero than the one you wish to train. This kind of training is not only free in terms of resources, but also does not occupy your stronger hero, allowing him to participate in battles as normal. Master Training raises hero's level by 10, as long as it doesn't exceed the trainer hero's level. The level cap still has to be raised normally, through Basic Training.
Master Training Edit
There are two possible ways to level up the Heroes after the Basic Training.
The first way is to play with the Hero to gain his experience (xp). The points will increase only if the the battle in PvP is won. There are Artifacts which help to increase the xp.
The second way is the Master Training. The Master Training is only possible if there is a Hero in a higher level. The Master Training is free and available after the Basic Training. The Hero in a higher level will be the Trainer.