Junior Sister and I Were Reborn as Monsters

After countless epochs of training, I finally reached the peak. Damn junior sister actually interfered with my tribulation! We both suffered a backlash and fell into the mortal world together. He became a water tower and I became a sea otter? It doesn't matter, it doesn't matter what I am reborn into, what matters is that I want revenge. The first step is to find a rock! The second step is to crack the shell of the crab and solve the problem of food and clothing! The third step is to lead the tribe to launch a counterattack against Junior Sister Otter who is competing with us for food! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.