The cave the sea lion used as its lair was big enough to fit both of them, so it did not mind having Arthur inside of it for a couple of days.
It was not a dumb beast, either. The power emanating from Arthur's body was incredible, way stronger than the sea lion. If it tried anything funny, Arthur could end its life in an instant.
Arthur found a place far from where the sea lion stayed, but only that would not bring him a peace of mind. So, he waved his hand and cast a mana barrier around him.
With the amount of mana he had, it was easy to keep it working for a few days. The mana barrier would usually cost more mana if someone attack it, and if that happened then Arthur would try to stop his breakthrough for a few seconds and kill whoever it was.
The moment Arthur sat on the rock ground, a black substance enveloped the surrounding area, engulfing his body in complete darkness.