Defeated 20 consecutive enemies, without being hit
This can be done in the very beginning of the game. Go to the room were you get the Slide Attack. After you have taken it, go back to the right and slide through the small gate. The enemy on the other side will respawn everytime you go back and forth through the gate. Kill him and Slide back and repeat. This is a good way to get this Achievement / Trophy quick and save right at the beginning.