for this achievements you will have to become the master rank in the virtua fighter 5 quest mode.
you will notice that when you fight you will have a little bar at the bottom of the screen that fills up ot drops at the end of the match depending if you have win or lost.
to get the bar to fill up the fastest beat an opponent that is the same rank as you. you can also beat an oponent who is within 2 ranks above or below you but this will no fill your bar as fast.
the ranking system for virtua fighter 5 :
10th Kyu to 1st Kyu
1st Dan to 10th Dan
After the Dan ranks, a character's title is dependent on winning percentage.
If a character's winning percentage is less than 70 percent they will obtain the following ranks:
Master -> Defender -> Enforcer -> Sentinel -> Protector -> Guardian -> Paladin -> Liberator
If a character's winning percentage is between 70 and 80 percent they will obtain the following ranks:
Master -> Hunter -> Raider -> Barbarian -> Assassin -> Slayer -> Berserker -> Destroyer
If a character's winning percentage is above 80 percent they will obtain these ranks:
Master -> Warrior -> Veteran -> Gladiator -> Vindicator -> Avenger -> Vanquisher -> Conqueror
just beat 5 10th dans in a row to get to the master rank be warned tho if you loose against a 10th dan opponent you will be demoted and you will have to start all over again.
the best method is once you have beaten a 10th dan opponent exit the next match and save your progress. if you loose switch off the console straight away and load up the game.