This Seeking Tech guide will explain how you can earn the Jeanne d’Arc called Beware the Wild Prairie.
This trophy will be unlocked when you beat the Altois Prairie stage for the first time. This location will be available after you beat the 12th stage of the campaign.
For the prairie, make sure that most of your party is at least level 30. You should also have magic spells equipped, in addition to bringing as much healing as possible.
The Sweep special attack and Cyclone 2 spell are extremely helpful here. So you may want to get them first to make the fights easier.
At the start of the stage, place your best characters on the southmost side. On the first turn, move them towards the Dragon and attack if possible. Try to keep your party spread out against the bigger enemies to avoid area attacks.
On the second turn, you should surround the dragon with one character on each of his four sides. This will limit his attack to one character per turn. Afterwards, try to take down the dragon as soon as possible before the crow enemies come over. The Sweep and Cyclone 2 attacks work extremely well against dragons and other big enemies.
After defeating the Dragon, turn your focus towards the Qrow Leader and Qrow Knights. These enemies have a high evasion rate, so you should mostly attack them with magic.
With the crows defeated, attack the Queen Rouge next with mostly magic attacks since she has a high evasion rate as well.
After beating the queen, fight the Golem next to her. Use the same strategy as you did with the dragon.
The three remaining enemies are located on the eastern side of the map. Try to take them down one at a time using the same strategies as before.