As many fans would know, just after Goku drew with Tien during the 22nd World Martial Arts Tournament, King Piccolo was released from his seal by emperor Pilaf.
The demon king was sealed by none other then Master Roshi’s teacher, after Master Shen (Roshi’s friend and rival) and Roshi, were defeated by Demon King Piccolo.
Master Mutaito, was the name of Master Roshi’s teacher and he was the one who invented the Mafuba.
The reason Mutaito needed to use the technique was because of the Demon Kings incredible power and that it was the only way they could face him and ultimately save the world.
As a result Mutaito was able to defeat Piccolo and seal him away with the Mafuba, but due to the amount of kai the technique required, Mutaito passed away soon after.