This piece of advice I have is for those who have autofire (turbo, rapid-fire, in other words) controllers and want to not do a lot of work for the Vanquisher and Tekken Lord achievements.
Go to the controls menu and bind the LK+RK buttons to A.
Head to the options menu, place the rounds to one, with the difficulty set on Easy.
Enter Ghost Battle.
Either Solo or Tag, it doesn't matter as long as you pick Jun as your first character.
Then turn on the turbo for A, place an item down on it, and Jun will keep using her wheel kick move, over and over again.
Once all that is done, just stay away from your XBox for a good while and eventually, both achievements will unlock. Today, I managed to get Vanquisher and will hopefully get the Tekken lord achievement. I don't know if this will help in getting the Fortunate Fighter achievement, but I hope that it also unlocks as well. But there you go; an easy, lazy way to earn both achievements, should you have turbo controllers in possession.