Majestic Thunderbolt

Two rival bosses of diamond smuggling outfits, Tiger and Franco, get into conflict over a very valuable diamond. Tiger is an apparently conventional businessman. Franco is a psychopathic playboy whose pride and lust know no limits and who murders his own mistress for her infidelity.
It is smuggled into Hong Kong by Richard who tries to make a deal with Franco but Tiger hears about this deal and sends in Philip, a New York assassin, to steal the diamond. Richard's girlfriend is killed by Franco's assassin.
Tiger gives the diamond to Jack his future son-in-law, to sell, as Jack is a legitimate businessman and not interested in shady deals. Unfortunately Franco discovers Jack's operation and sends his men to kill Jack and fetch the diamond.
This causes Jack's brother, Alan, an ex-professional killer from New York to take up the cause of avenging Jack's death. He ruthlessly kills all those who were involved in his brother's death, and also kills Tiger with the help of Richard, and dupes Franco into killing himself. Richard, who has all along been trying to retrieve the diamond, finally kills Philip.
This is a film full of double crossing, greed, revenge and decadent luxury — with magnificent fighting scenes.