Activating this trainer:
If not state otherwise below, press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.

Promo Options:
Stats: Level

Trainer Options:
NumPad1: Unlimited Health
NumPad2: Easy Kills
NumPad3: Easy Boss Kills

Editor Options:
Points: Set Stat Points
Points: Set Skill Points
Stats: ATK
Stats: ATK SPD
Stats: DEF
Stats: CRIT
Stats: HP
Stats: Level

Notes:

For the Editor, if you change stats, you may have to spend a STATS point for it to update the true value used in the game.  If you use very high values, and want to be able to undo it, then set the stats value to a low value and then spend a point to undo it.

Unlimited Health: Toggle on and most things cannot harm you.

Easy Kills: Toggle on and most foes die quickly.

Easy Boss Kills: Toggle on and most Boss foes can be killed very quickly.