Once you enter the character select screen in a multiplayer battle, hold in both the right and left triggers and you will see the names of the monsters. Select one and go to the next screen before letting go of the triggers.
As you may not know, environmental skills leave crystals as where you stand when you use the skill. To undo the skill you just pick it up as if it were a skill. Beware some environmental skills will or may be harmful to you as well.
When you first start the battle you fight only one of the sisters. So when she goes green and does her punch attack jump and dodge it then while still in the air attack her. do this until you have beaten her. Then the other 2 sisters come. do the same thing with these and you will beat them. it may take a few tries but it works.
GamesRadar is the premiere source for everything that matters in the world of video games. Casual or core, console or handheld - whatever systems you own or whatever genres you love, GamesRadar is there to filter out what's worth your time and to help you get even more from your games. We deliver the best advice, the most in-depth features, expert reviews, and the essential guides for all the top games.