You must fill the character's heart meter to the maximum level.

: Using the piston to strike a mob specifically on the top of the head.

To unlock the "Lovely Craft Piston Trap" achievement, you'll need to meet the following conditions:

: This is achieved by interacting with the character until their "hearts" (an in-game affection or pleasure meter) reach the maximum level.

Jax scrambled to rip his headset off, knocking a glass of soda onto his keyboard in the process. The short-circuit caused his character to hold down the 'drop' key. He watched in silent, ringing horror as his enchanted sword fell into the piston teeth and was deleted from existence.