Use this template and add your own oc instructions: Step 1: replace that white guy with your oc/ boss Step 2: set the health variables to whatever Step 3: add your own music Step 4: code your own attacks (there is no template for that, you need to add your own)
To add damage sensors, there is a comment inside (look in the "heart" sprite also, -arrow keys to move -space on attack button to attack -get green heart to heal