Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey.All hotkeys can be changed on the trainer.

Trainer Options:
NumPad1: Infinite Health
NumPad2: Unlimited Water
NumPad3: Unlimited Hearts
NumPad4: Infinite Power
NumPad5: Freeze Mission Timer
NumPad6: One Hit Kills
NumPad7: No Cards Cooldown
NumPad8: Change Zeni By 5000
NumPad9: Change Medals By 500
NumPad0: Super Speed
NumPad/: Slow Motion 0.3

Editor Options:
Misc: Medals
Misc: Zeni

Notes:
Zeni: Visit shop and return back to menu. Now press hotkey and enter shop again to see it has changed.