Capítulo 451: Training! Debates and an introduction.

Since the young Electus will be departing on a large quest, alone and won't be in Gaster Kingdom in a long time, King Michael urged for him to put as many hours as possible training his Healing powers.

Ladia won't be there to patch his wounds, neither will be Mogranius to cover for him if Eric got hurt in between some battle. He will be alone out there, so he must be prepared.

I'm sure you already puzzled together why he will be going alone, it's because Gaster Kingdom needs every other Fire Controller here, or else this Kingdom will collapse before two of the 10 relics are recovered. 

Since Eric won't be departing too soon, such as going tomorrow. He does have a few days at least to train, Ladia has been assigned to teach the young Eric 8 hours a day.

Furthermore, the young boy won't be holding any shifts so he can solely focus on his Healing powers. In other words it means Mogranius and King Michael will be holding 12 hour shifts, at least until Dilli arrives.