The only condition for free use is a credit line. Personal YouTube videos and streams are free even if monetized (promoting a company or paid client work needs a license).
A battle voice for scenes of rapid-fire strikes or attacks, like the "ata-ta-ta-ta" combo hits from Fist of the North Star. Try looping the middle "to" sound to play "to-to-to-to" during the attack, then finish with the final "Too!" for a satisfying combo effect.
