"The "Chi Cannon"...A move of enormous destructive force... Many times more powerful than even the Kamehameha... Its power is so colossal, in fact, that the drain on one's own energy is devastating... Warriors have been known to die by using it... And even if one survives, one's life is shortened..."- Kame Sen'nin (DB132)
The Kikôhô, otherwise known as the 'Chi Kung Pao' or 'Chi Kung Blast' is a technique of the Crane School and one of the most powerful chi exertion methods ever developed in the Dragon Ball universe. It is an amplificative chi blast that deals more damage than the source should actually physically be able to produce, by drawing energy from the users actual life-span. In fact, the technique has been known to kill the users in the past, for example Tenshinhan used a full powered Kikôhô against Nappa and died.
The power of the technique was illustrated by Tenshinhan at various points, most notably during the battle with Cell. Cell was a being who's power completely overshadowed Tenshinhan's, yet he was able to keep him at bay by repeatedly using the chi cannon on him until he collapsed from exhaustion. Tenshinhan was also able to help during the fight with Boo, deflecting one of his chi blasts using the cannon.