A tips for the "Mask Another’s Memory" achievement:
Start off by doing a bad arcade run. Try to avoid doing ringouts, and use a couple of continues if you want. Just make your completion tims as bad as you can/wish. Then, go to the leaderboards; your score, and then you can scroll down to see people with even worse completion times. Register one of those as your rival, then play through arcade again. You should get the achievement easily.
This is how I did it. Takes an extra run, but whatever. Also, Yoshimitsu is great to use for this, since his 214A+G grab can be used for ring outs if you have your back towards the hole, and 6B+K,B,B,B (I believe it is? The door knocker) can be used if your opponent is close to the hole.
In stages without holes, you can use the aireal suicide to get your opponents health down by like 60%. You can basically use an aireal suicide and a Critical Edge to win a round, they'll get like 1 HP left, tops. Doing aireal suicide is risky of course, but it's a fast way to beat the CPU, since they'll rarely try to hit you in the air, and if they avoid it by moving, it's probably just a fluke.
Last edited by Doopliss SWE; 02-09-2012 at 12:36 AM.