Fortify

In game description- "Upgrade barricades and turrets! You can't make new ones, though."

This is a non-unique ability so it works for everyone.

This is a strange and situational ability.

If there are many turrets and barricades initially in a round and, you keep them alive then, this has use because,

it only takes up 1 of 3 slots but, you cannot make new ones so, it's your choice to even ever use it.

This can be purchased and upgraded at the Mojo-Dojo

Since this is an action-skill you must press selected button to activate it.