Once selected, your first fight is against Ms. Fortune. Easy fight, really. This'll be another one of those characters where one combo = victory. Just spam LKx2 > MKx2 > HK (Low Kick twice to Middle Kick twice finished off with High Kick).
Your second fight will be against Filia. I know these guides are becoming a little repetitive, but spam the combo from the first fight Vs. MF to win.
Your third fight is against Painwheel. I did take some damage during this fight, but it shouldn't matter whether you take damage or not. Just spam the combo from the first fight for success.
The fourth person you fight is....yourself. Same goes here, just spam the combo from the first fight to win.
Your fifth fight is against Double and Valentine. This time around, Double is the first in line. Combo Double before she can combo you, Double has ruthless combos with no escape.
Once Double is down, Valentine joins the fight. When she comes in, you may take some damage. Don't sweat it though. Valentine is - you guessed it - easy. Combo her back to Med School to defeat her.
Once Valentine and Double are knocked out, you'll move down to confront Marie, the Skullgirl. Click "Next Page" to see the simple guide for fighting Marie as Parasoul.