1. Yakushi Kabuto first appeared as a weak participant in the Chunin Exams, but later proved to be incredibly powerful. 

2. Suigetsu, initially appearing weak, was actually a hidden Tailed Beast-level ninja. He dared to challenge Sasuke and fought equally with the Sanbi. 

3. Kurotsuchi, a member of Akatsuki, appeared mysterious and weak. However, she unexpectedly revealed her true power by swiftly killing the god-level character, Shin Uchiha. 

4. Konan, the only female member of Akatsuki, initially seemed unskilled in combat. However, she recruited defeated Akasuna no Sasori and nearly killed Tobi with her powerful technique. 

5. Kitsuchi, an elite jounin from the Hidden Stone Village, appeared ordinary but surprised everyone with his impressive abilities. He stunned the Five-Tails Jinchuriki with a single punch and restrained the Gedo Statue and Ten-Tails.