The hand sings used by Oro during his animations for blocking/parrying an attack, using his normal fireball, or using his Yagyou Dama super art, are know as mudra, which are symbolic or ritual gestures from the Hindu and Buddhist faiths; later on incorporated into various eastern styles of martial arts. Additionally, Oro draws Ki energy from a specific part of his body depending on where his hand is placed, for example, if Oro placed his hand on his head he's drawing energy from the brow chakra, and when placed on the chest he's drawing energy from the heart chakra.
Contributed by ZpaceJ0ck0