The Chu Heavenly Clan's Forbidden Area is the location the Chu Heavenly Clan decided to send Chu Xuanyuan to serve as punishment for his drastic actions of killing members of the Wuming Clan. In the Eastern Sea Region,the Chu Heavenly Clan's Forbidden Area is known as the Heavenly Road. It is a passage that connects the Eastern Sea to the Holy Land of Martialism. In actuality the Chu Heavenly Clan's Forbidden Area is a place used by the Chu Heavenly Clan to punish offenders of the clan.
The Chu Heavenly Clan's Forbidden Area has a special power that inhibits Bloodline Powers and slowly destroys an individual's Cultivation the longer they stay within it. Many Cultivators believed that after spending so many years in the Chu Heavenly Clan's Forbidden Area, Chu Xuanyuan would have had his cultivation degraded to a pitiful state, which is an incorrect assumption that couldn't be further from the truth.
In actuality, the real reason Chu Xuanyuan returned to the Ancestral Martial Starfield was because he wanted to explore the Chu Heavenly Clan's Forbidden Area. Chu Xuanyuan discovered that there was another power hidden in the realm. This powers nature can be seen as extremely similar to the Bloodline Strengthening Power bestowed by the Mysterious Black Box Xianhai Shaoyu andChu Feng assimilated with. However a slight difference can be discerned, as the hidden power within the Chu Heavenly Clan's Forbidden Area releases the full potential of an individual's Bloodline Power if they are able to comprehend its profundities.
According to the Old Ape, his current cultivation was granted to him by this hidden power within the realm Ch 2662. It is worth remembering that before this his cultivation was even below that of an Exalted due to the restriction of the realm, but now Old Ape possesses power far greater than any Cultivator in the Holy Light Galaxy. This is a testament to how incredible this hidden power within the Chu Heavenly Clan's Forbidden Area truly is.
In the case of Chu Xuanyuan, it is unknown what kind of benefits he gained from the Chu Heavenly Clan's Forbideen Area but they cannot said to be small, since after training there for over 30 years he was able to gain strength that allows him to move unhindered throughout the vast Starry Sky. This can be seen when Chu Xuanyuan was able to easily defeat the Galewind Hunting Clan's Ancestor, an existence from the Ancient Era who is so powerful Xianhai Shaoyu believed that few within the current era could defeat it.
The last time Chu Feng visited the Chu Heavenly Clan's Forbidden Area his father had already left, however Chu Xuanyuan left behind a powerful spirit formation only Chu Feng could pass. Within the formation was a message telling Chu Feng that the hidden power within the realm can awaken the Heavenly Lightning Bloodline's hidden potential and in his own words, if Chu Feng was able to comprehend the power he would "attain a complete transformation" [3095]. Merely the Chu Feng at the time, with a cultivation of 6th Rank Heavenly Immortal, was simply too weak to comprehend the powers of the realm and fully awaken his Heavenly Lightning Bloodline. Showing that one needs a high cultivation before they can attempt to fully comprehend one's Bloodline Powers.
Book 9 - Birth of Asura
The Demon Morph Clan, who are known to use ruthless methods to gather treasures that can allow their strength to grow, came to the Holy Light Galaxy in search of a hidden power they believed could help them explosively and permanently increase their strength. According to Xianhai Renhu, the hidden power they seek is able to evolve Heavenly Bloodlines to a currently unknown state, but it can be assumed that an evolved Heavenly Bloodline is something that can allow a power to reach the peak of the Martial Cultivation World. To reach their goal, the Leader of the Demon Morph Clan led all the top experts of their group to search for this power, but were thwarted and captured by Chu Xuanyuan, who had already used the power within the Forbidden Realm to evolve his own Bloodline. The Galewind Hunting Clan Ancestor, a powerful being from the Ancient Era, was shocked that a cultivator from the Modern Era like Chu Xuanyuan was able to train his Heavenly Bloodline to such a level, which might show that even during the Ancient Era people who can make their Heavenly Bloodline reach such a level are rare.