While in the Yu Heng World, Han Yi encountered evil beasts during the Qi Cultivation Stage. Those were creatures who had not yet fully gained their wisdom and couldn't be called members of the Evil Clan.
When he advanced to higher realms, the demon cultivators he met were of all forms and varieties. He had contact with demon cultivators in places like the Evil Mountain, the Stars Sea, the Seven Beidou Region and the Qingxuan Daoist Site.
Ironically, he found himself in the Illuminating World and then in the Tianquan World. The Illuminating World was essentially the world of the Evil Clan, and half of the Tianquan world also belonged to the Evil Clan.
Therefore,
Han Yi knew quite a lot about the Evil Clan's cultivation methods.
If one says that the Immortal Path cultivates 'laws' and 'arts', and the Ancient Gods cultivate 'body' and 'strength', then the Evil Clan cultivates simply one core - 'bloodline'.
