Phrase Meaning – Meaning of ‘We Are Following Up on the Correspondence Below’

Consider:

I am awesome.

This is a general statement of my state, claiming that it is awesome.

I start being awesome.

This is a claim that I move into the state of being awesome; I was not awesome before, and then I am. It also suggests a degree of agency (I am active in being awesome).

I am being awesome.

This is a rephrase of the first using a doubling of to be to add an emphasis on my agency in being awesome. It's rarely sensible, often awkward, and once very controversial even in more complex forms ("You will be glad to hear, under my own hand (though Rice says we are like Sauntering Jack and Idle Joe), how diligent I have been, and am being." - Letter from John Keats to John Hamilton Reynolds, July, 1819).

Here Keats at least has the excuse that he wants to combine both "have been" and "am being", though some would still say he should have said "...how diligent I was, and am".

Now consider:

When I'm sad, I stop being sad and start being awesome instead.

Standard English, and reflecting a degree of agency, along it being a change of state.

When I'm sad, I stop being sad and am awesome instead.

A change of state is implied by the rest of the phrase, but not by "am awesome" itself. There's nothing to hint at a degree of agency other than it being claimed as a general policy toward sadness. There's a clash between "stop being" and "am", bordering on syllepsis.

When I'm sad, I stop being sad and be awesome instead.

A stronger emphasis on agency, and combines both a claim to always be awesome and a claim to actively be awesome in response to sadness. Be is clearly not used normally, but favouring it over am ties it to the earlier being in a use that again is close to syllepsis.

It's certainly not playing by the rules, but that fits the character, and it's all the more effective for that.

Is my vision plain wrong because of some English sentence structure rule?

No. English sentences are often ambiguous. But you might still be wrong for other reasons.

Let me try to rephrase the two interpretations:

1. An already-shaken opponent, when hit by you, becomes flat-footed to your attacks.
2. An opponent previously hit by you becomes flat-footed to your attacks whenever they are shaken.

One of these interpretations probably makes more sense within the internal logic of the game. If so, the "vast majority of people" you've spoken to might not have even noticed the ambiguity because they read it with what was to them the obvious interpretation. To resolve the ambiguity, I think you have to look at the context, both the surrounding rules and the text explaining the motivation behind them. Ask yourself: Does being in the "shaken" condition cause other effects similar to interpretation 1? Does having been previously hit by you cause effects similar to interpretation 2?

Speaking of context, I wonder if there are lots of rules governing the transitions in and out of these conditions or states of being. Perhaps the manual spelled out the first transition rule in great detail, and expected you fill in the details (by analogy) on subsequent, tersely-stated rules.