Here you go Edwoodjr something for you to reach for this is uploaded on wiki also
So far ive noticed:
Stringing pummel + magic mortar = Fusion ?
Magic mortar + stringing pummel = Gravitation
Armor piercer + stringing pummel = Darkness
Tachi Gekko + Stringing pummel Darkness
Average Dmg 800+
Highest to date 1500+