My Sister from Another World Is so Invincible!

My name is Ling Dong, and I am a traveler! Being able to travel across all realms is just a bit out of control. There is a "Be my sister" system, but it's a bit unreliable. There is also a father, Ling Tianjiao, whose strength is incredible, but he almost does not exist. I have been to many worlds, some of which are capable of cultivating immortals, some of which are electronic worlds, and some of which are dilapidated. There are still a few sisters in the different world I traveled to. Since the system upgrade, I can bring them back to Blue Star. But I don't think they need me to find them. Because they are so invincible! It feels like it won't be long before I can break through the void, find it yourself! With such an invincible sister, let alone spiritual energy recovery, even a terrifying recovery, what can I do? This book is also called About the Invincible Sisters and Their Useless Brother, Why the Burden of Saving Blue Star Falls All on Us, and World-Class Tool Man. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.