"Mana" is a concept every Maori and All Black would know. All Black captain in the late 80's, Wayne "Buck" Shelford, once had his scrotum torn open during a test match. He left the field, had the wound stitched in the change-room, and returned to the field of play ten minutes later.
He had "mana". Especially as, under his captaincy, the All Blacks never lost a test.
It combines admiration for someone's high position, his natural respect-attracting personal aura, his ruggedness and strength, his proud record and legacy, the dignified way he conducts himself among people ranked above him AND below him.
If you don't respect someone's mana by doing or saying something insulting or demeaning, you trample on his mana. And if you do that, you invite "utu", or revenge/retribution.
So, always respect someone's MANA, if you know what's good for you.