The reverb rod's getUseAction() method returns UseAction.BLOCK, which in addition to visually blocking also makes the rod function as a vanilla shield.
To reproduce, inscribe any spell into a reverberation rod and conduct it while being shot with arrows or being attacked by a player wielding an axe. Arrows will be blocked as well as melee attacks, even yielding no cooldown when being attacked with an axe, albeit playing the "guard break" sound effect.
Confirmed that its use of UseAction.BLOCK is the culprit, now testing the other available UseAction options to find one that looks good and doesn't have obvious side effects
The reverb rod's getUseAction() method returns UseAction.BLOCK, which in addition to visually blocking also makes the rod function as a vanilla shield.
To reproduce, inscribe any spell into a reverberation rod and conduct it while being shot with arrows or being attacked by a player wielding an axe. Arrows will be blocked as well as melee attacks, even yielding no cooldown when being attacked with an axe, albeit playing the "guard break" sound effect.