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: Infinite GP
NumPad3: Infinite SAN
NumPad4: One Hit Kills
NumPad5: Weak Enemies
NumPad6: Infinite Move Range
NumPad7: Change Energy By 5000
NumPad8: Unlimited Items
NumPad9: Change Level EXP By 500
NumPad0: Change Gift EXP By 5

Editor Options:
Energy
Selected Character: Maximum HP
Selected Character: Maximum GP
Selected Character: Maximum SAN
Selected Character: STR
Selected Character: VIT
Selected Character: PSY
Selected Character: DEX
Selected Character: AGI
Selected Character: CRI
Selected Character: MOV
Selected Character: Level
Selected Character: Level EXP
Selected Character: Current Gift EXP
Selected Character: Maximum Gift EXP

Notes:
Weak Enemies: While active enemies have no GP and no SAN.

Infinite Move Range: While active you can move around in your circle as much as you want without limitations.

Energy: In lobby press hotkey to add more then visit item screen to see it has changed.

Unlimited Items: While active open your item screen and all visible items are unlimited.

Selected Character / Level EXP / Gift EXP: Open the status screen of the character you want to edit. Make changes or use hotkeys then switch to another character and back to see it has changed.