This is arguably the most powerful combination in the entire game. The Shield Rod is a unique weapon found in the Long Library. When equipped in your right hand and used in conjunction with a shield (equipped in your left hand) by pressing Square + Circle simultaneously, it performs a special attack. The effect varies depending on the shield.
When combined with the Alucard Shield (found in the Inverted Castle), this combo unleashes a devastating barrage of attacks that deals massive damage to all enemies on screen, often healing Alucard simultaneously. It consumes a significant amount of MP, but with high INT and MP regeneration, or the Duplicator accessory, it can melt even the toughest bosses in seconds. Master this combo for an easy path through the Inverted Castle.