Capítulo 1566: Star Thief.

They are going to hide in a realm tree because they are sure that being outside a realm can't be safe for them right now due to the search of world gods. They will continue to strive to gain the assistance of the High Heaven Realm and won't give the Supreme Alliance the benefit of crawling back to them. 

To achieve that, Legion-8 is corroding the Tyrant Realm, while Helios is responsible for plunging the realm into darkness.

It wasn't only the tree father and Legion-8 that entered the realm for the mission to accumulate contributions. Helios also entered, and the Supreme Beasts probably noticed him, but they avoided him. Instead, they went after Legion-8. 

It could be because Helios was doing dangerous work, and they didn't want to die by coming closer to him. After all, the full power of a star can only be rivaled by world gods. For someone to start eating a star, he must not be one to be trifled with.