Never

"Months prior to their lockdown, reports stated that they used the Void Tunnel we commissioned the construction of for Little Saru's trial. In all likelihood, their destination at the time was either the same as Little Saru's, or very close. 

"We know that Head Void led a group of Void Clan disciples personally, all of whom were excellent celestial warriors. But, none of them came back. 

"Soon afterward, the now dead Head Void's son, Kaori Void, forcibly took control of the Kitsune Clans using their 'Ancestor's Command' token. However, this was only after being elected the next Head Void by garnering the support of two geniuses that should have been his competitors – Fourth Elder Nobu Void and Fifth Elder Midori Void." 

King Shruti sighed. 

"We don't have much information other than this. We weren't worried initially, because we thought there would be some leaks. But, they really sealed themselves off."