WARRIORS OROCHI 3 Ultimate

If you're having trouble with this achievement I recommend beating the gauntlet mode first to unlock Hundun and get his card, which will make this achievement childishly easy.

The setup that you want to use is this, the characters you pick do not really matter but the better picks would be Ding Feng (for his grapple attacks and default charge attack spam), Huang Zhong (for good ranged attacks and aerial escape) and Shennong (for the resurrection skill and powerful heal from his special).
The cards you want to use are:
Strategist's Dealings (Motonari Mori's rare card found under "special")
Red Beans (Oichi's normal card found under "support")
Power Without Limits (Hundun's normal card found under "attack")
Fiendish Rose (Rachel's normal card found under "impede")

This whole strategy revolves around Hundun's card which costs only 2BP and creates an orb that fires projectiles that do ungodly amounts of damage and stack multiple times and on top of that can hit the enemy at any point, even when they're down on the ground or in the middle of being grappled. We also have Motonari Mori's card which costs 0BP and gives you 3BP right off the bat. Then there's Oichi's card that also costs 0BP and gives you 2BP, as well as Rachel's card which costs 3BP to use and disables your opponent's movement keeping them away from you and making it easier for them to be hit by Hundun's card.

Now, what you want to do is, soon as the battle starts, pop Strategist's Dealings and Red Beans then activate Power Without Limits and Fiendish Rose. All you need to do now is get some distance from your opponent, stand there, and block while watching them get nailed by Hundun's card while their movement is disabled. The damage your opponents will be taking from Hundun's card will give you plenty of BP to keep stacking it up over and over and use Rachel's card whenever it becomes available again.
If your opponent gets to close for comfort while able to move, you can do a few things to keep yourself relatively safe. You can just continue to stand there and block while parrying every chance you get, spam Ding Feng's base charge attack (Just keep hitting the Y button), run around and use his sprint attack, or use Huang Zhong’s EX attack (XXXX YY). I’d stick with with the block/parry thing, but whatever you chose to do you should be okay.

With this particular setup I can easily get up to 210 wins in survival (though past that point it's completely worthless since your opponents have infinite guard-parry) but you should have no problem getting 50 wins needed for the achievement. Good luck.

This one can be a bit tricky depending on the set up you make. First off however to access this click Duel mode and then go into Survival mode. Your tasked with K.O'ing as many officers as you can. You'll be faced up to 3 enemies at a time or more so one team at a time. It'll be 1v1 through out the whole thing but you can switch to other allies whenever(like story mode and ect.)

They easier way I did it was to have one character that was good at close range, one at distant range and the third one isn't needed. If anything I would go with another distant attack character. Personally for me I went with Sima Zhao, Lianshi, and Ding Feng. Lianshi for the most part will be your go to character. You'll also be granted to use Strategy cards that you've earned up to that point.

My Strategy Card set up was this:
Healing Harmony
Moon Viewer
Fiendish Rose
Fighting Spirit

Moon Viewer and Healing Harmony are the two key cards that'll get you through the 50 officers without much difficultly. Stay back and do combo moves with Lianshi and they should hardly have the chance to attack you. With moon viewer it will heal and replenish your musou gauge. That comes in handy during pinch moments and when the enemy has tough defense. Other than that it's just based on luck with what officers you must fight. I got paired with a few that mauled me regardless of my tactics. Other than that happy hunting and hopefully you can earn this. :)

Note* Once you eliminated 30 officers the map will change. Your streak will still be there so don't worry. I just changes every 30 along with the more officers you defeat the tougher they become.

If you have any questions let me know and I'll help you guys out.