Kraftvoll decided to enter deep meditation inside the cave as soon as he secured his safety. While he was doing this, the shadow familiar that he just recently freed from the rubbles was assigned to guard the entrance of the ice dome he was in.
Inside that cave, only dark seishin essences, earth seishin essences, and some wind seishin essences were the most abundant sources of inner seishin essences that Kraftvoll was able to gather to his inner seishin essences reservoir.
The cave where Kraftvoll was hiding does not have any light in it except for his Luminous Orb seishin spell that he conjured earlier so he did not have any source of light seishin essences. While the sources of fire and water seishin spells were not that much either so only the other three were the only ones that Kraftvoll managed to absorb to his reservoir.