Many people have trouble beating levels 19 and 20, so here are some step by step instructions to winning.
Level 19 1) Using Yoh's friends defeat the three Millennium Force guys holding up the barrier. (Just double team on them.) 2) Using ONLY Yoh move right up to Masked Maril. 3) Instead of battling her, go to Yoh's options (where you have the options to move or fight) There will be an extra action called "persuade", use it and Yoh will start to fight Maril. 4)Beat Maril to half life. 5) You beat Level 19
Level 20 NOTE: There are two different endings to this level. To get a good ending, DO NOT use a map type weapon or special ability. To get a bad ending use a map type weapon or a special. 1) Use Yoh's friends to defeat the Millennium Force leaders. (It is OK to use Yoh, as long as he doesn't die. You don't HAVE to beat any of the leader's henchmen. I recommend somebody stays with Yoh just incase. 2) You have to battle Zeobide, make sure he doesn't battle you. So I recommend you check his capability and stay out of his attacking range, and attack he is in your advantage range. I also recommend to use a strength talisman on Yoh and the person that's helping him. Then you should save. 3) Fight Zeobide. Block all his moves and hit him at any open opportunities. DO NOT kill Maril, or its a game over. DONT use too much furyuku, because you have to use an ultimate attack. When you have two claws of venerability full with color, the circle that fills up with colors with three claws under it, Use Halo Blade, L1+R1 and up. Make sure Zeobide does not block it. A picture of Amedamaru and You should show up. Zeobide will lose alot of health but probably wont die so while he's down run up to him. When he gets back us keep on hitting him, dont allow him to hit you!!! If you do this correctly Zeobide will die and you will pass the game. Dont turn off the game!!! Save and go to the main menu, there will be a Versus mode. You can change some players by pressing select on them. So enjoy!!! NOTE: IF YOU SKIP STEP 1 OF LEVEL 20 ZEOBIDE WILL REGAIN HEALTH.
You will learn this special move after you read the Tome Of The Shaman. Press L1 + R1, Up to execute it.
In versus mode, press Select on Yoh to get Zeke. Press Select on Meril to get Masked Meril. Press Select on Kanna to get Matilda and Marion Fauna (the two girls that fight with Kanna).
Beat all 20 episodes of story mode to unlock the 2 player vs. mode feature.
Successfully complete all twenty episodes in story mode. The versus mode option will now be unlocked at the main menu. You can play as Vineuvail, Zerumo, Lyserg, Heckel, Tao Len, Faust VIII, Ruby, Kanna, Lee Pai Long, Trey, Zaua, Meril, Rio, and Yoh. You also get one random secret character, such as Silva or Zeke.