have you ever read manga..especially sport manga which exaggerate skills or technique and made it sound difficult to do? when actually in real life its not really that hard, with practice anyone can do it. which manga you have read that actually did this?
Technically speaking... kamehameha can be done by anyone. It's literally a form of energy moving, and based on some alternate versions, it can also mean a gust/ball of wind. If you gather your hands and make a thrust, you will make air rushed forwards. tada~ you're already done. xD exaggerate about a quadrillion times and apply tornado-like effect with dust/debris (which comes naturally if it's that much stronger), you got yourself a fully visible ball of energy (which is transferred through a medium of wind) moving towards your target.