The trainer i used onley worked for gold and ordenary fighters, the bosses you had to kill them on your own. I know that in the beginning some npc's vanished and i had to restart the game with only gold option and life. So yes i do think if you uses easy level up the NPCS vanish, that's why i didnt use that option.
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem