If Super Blocks can be performed often, the healing effect may be able to nullify damage taken, as long as the damage is low enough. Additionally, if a Super Blocked attack reduces the equipped bug's HP to 0, it will be recovered to 1 instead of the party member being KO'd. This means that that the bug cannot be KO'd by Super Blocked attacks, only reduced to 1 HP. For multi-hit attacks, only the last hit needs to be Super Blocked for this effect.
How to Acquire
There is 1 Block Heal medal available. It can be found after defeating Chapter 4's boss and going to back to Snakemouth Den to complete Leif's Request, which only requires the Peculiar Gem, and not the Other Ancient Half, making it technically possible to obtain before officially completing Chapter 4.