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:

NumPad4: Unlimited Oxygen

Trainer Options:

NumPad1: Super Weak Enemies
NumPad2: Fast Reset Skill Cooldowns
NumPad3: Unlimited Potions
NumPad4: Unlimited Oxygen

Editor Options:

Current Combat Unit: Current HP
Current Combat Unit: Current Mana
Character Stats: Current Level
Character Stats: Current HP
Character Stats: Current Mana
Character Stats: Current XP
Character Stats: XP Require for Next Level
Character Stats: Current Attribute Points
Character Stats: Current Talent Points
Character Stats: Current Strength Value
Character Stats: Current Agility Value
Character Stats: Current Intelligence Value
Character Stats: Current Wisdom Value
Character Stats: Current Vigor Value
Resources: Current Gold Amount
Resources: Current Firewood

Notes:

EDITOR OPTIONS
For Current Combat Unit, while in combat, the Editor will display the current HP and Mana of the unit whose turn it is.  Change a value, then press TAB to lock it in.

For Character Stats, you need to press P to enter the Party screen, then click the ATTRIBUTES icon to enter the ATTRIBUTES  page, then all the values for the currently selected character will fill in.  Change a value, then press TAB to lock it in.

For Resources, enter the Inventory, then note the values fill in.   Change a value, then press TAB to lock it in.

Super Weak Enemies:
Toggle on and the trainer tries to set the enemies health to low value, making them easy to kill.

Fast Reset Skill Cooldowns:
Toggle on and when you engage a skill, the cooldown before it can be used again is reset quickly.

Unlimited Potions:
Toggle on and when you use a potion, you have 3 of them.

Unlimited Oxygen:
Toggle on and when you enter areas that are flooded, you have unlimited oxygen to explore.