(I'll update first and revise later. Don't look at this line again.)
It's common knowledge that each Opening Heaven Divine Artifact can only open the heavens once.
The Opening Heaven Divine Artifact is a one-time use thing.
Does the Opening Heaven Pen have some... issues with the cannon mount?
An Opening Heaven Divine Artifact is the easiest to transform into an Artifact Spirit. Su He wonders when the Opening Heaven Pen will condense its own Artifact Spirit. Once it does, it will be a mature Opening Heaven Divine Artifact, and he could simply toss it into the Chaos and let it develop on its own. He just needs to harvest it periodically.
The Opening Heaven Pen is only reacting instinctively; it won't actually attack the cannon mount. Even if someone really managed to breach Su He's Inner World, the Opening Heaven Pen would automatically counter and safeguard the cannon mount.
