Gnome must be present before you can use the Gnome Prerequisite

Your relatives are so smart and are able to perform illusion magic. It is a well-known fact that the magic trick of disappearing when you hurt yourself is something you already know. The following are some other benefits you may enjoy:

This feat allows you to increase your Intelligence and dexterity scores by as much as 1 to maximum 20.

You can take the damage right away and use one reaction to make the victim disappear until your next turn. This applies up to the point you attack, deal damage, or force someone into a saving throw. This ability is not available more than once.