censure, criminal investigation
劾 centers on formal accusation and scrutiny: censuring someone or conducting a criminal investigation to uncover wrongdoing.
劾 combines 力 (strength, effort) with 亥, which likely contributes the sound and may relate to accusation or investigation. The exact historical development is uncertain.
The left side 亥 looks like a person under a roof, and the right side 力 is strength. Imagine an investigator using strength to bring someone under scrutiny for a crime.
For ガイ, picture a guy being investigated: guy -> ガイ, and the investigator is using force to censure him.
—