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:

Numpad 1: Invincible to Attacks

Numpad 2: No Damage From Mist

Numpad 3: Easy Crafting Materials

Numpad 4: Unlock Recipes

Numpad 5: Remove Crafting Equipment Requirements

Numpad 6: Unbreakable Items

Notes:

Numpad 1: Invincible to Attacks - you need to have been attacked and damaged at least once, then toggle this on, and most things that attack you cannot harm you.

Numpad 2: No Damage From Mist - when the mist is out and you find you need to move through it, walk into it to take a little damage, and then toggle this on.

Numpad 3: Easy Crafting Materials - press C to look at the crafting items.  Then toggle this on. Then leave and come back and even if you don't have the required materials, you can craft items if the other requirements are met.

Numpad 4: Unlock Recipes - press C to look at the crafting items.  Then toggle this on. Then leave and come back and most items are unlocked and can be crafted if the other requirements are met.

Numpad 5: Remove Crafting Equipment Requirements - press C to look at the crafting items.  Then toggle this on. Then leave and come back and even if you don't have the required equipment (i.e. a workbench, etc.), you can still craft the item if other requirements are met.

Numpad 6: Unbreakable Items - use an item that has a durability meter, then toggle this on and the item remains fully  durable.