The Opening Front Core Cannon is a Shiira Superweapon that can only be fitted unto the Pillar series at this time.
The weapon starts as a more triangular piece of the hull that can open up trough a sizor like manner (having joints on the inside for this), after the hull opened up you have a diamond shape between the ship and the joint and a large triangle opening between the 2 ends.
From this point on the Core Crystal will be charged up, building energy in its diamond shaped opening before releasing the blast from to opening between the ends as a massive blast of destructive power.
everything that is not destroyed by the blast will be covered by a dense layer of crystal.
see also: List of Shiira tech