As long as their continue to increase, he would definitely feel a lot safer, not to mention he felt that his cultivation got more faster as their speed of absorbing spirit Qi in the air increases, he couldn't wait to see what would happen if they ingest large amount of Mana.
He then opens his eyes and stretches for a bit as he felt his body filled with energy, after his wanton devouring he knew that his body is now full of chaos Qi, too bad there isn't much spirit Qi in the air, if it had he would definitely use this opportunity to breakthrough to the next cultivation realm.
When he got out he saw that the gloomy island is now a bit brighter, he knew that the scarabs were responsible for this, since they aren't able to advance to Saint Realm, they use all of their energy to cultivate the devouring rune on their body and soul.