Fighting a Colorless Halo Leviathan was no easy job. Ethan killed the first one easily because he used his strongest ability, but the rest were not so easy. Each and every one of them that he fought nearly took his limb, or some even his head.
His body was not nearly as strong as theirs. They were animalistic beasts with higher cultivation—even Dao Partner Art couldn't bypass that limit. Ethan was just a Mortal, and without his Dimensional Abilities, he was nearly a waste against the Colorless Halo Beasts.
Ethan's body was better than most beasts at his own level, but they were beyond his level.
He could only irritate them unless he used his Dimensional Shatter. But if he used it, he could easily kill them.