interesting thought process . . .

It goes along with what Gene Roddenberry maintained about humanity still being an adolescent species. Listen to the words that human adolescents hurl at each other.

This beats like such an argument. Lots of caesuras that stop the lines at odd places, yet it works.

But look at what you have here:

By pen; but, blood and steel and muscles taut

You get a full stop with the semi. Then, the comma after but stops it again, and it seems you don't want to stop here. You want to flow rapidly though to the end of the line, which it otherwise does. Dropping the comma would let it run.

This line's problem is the parenthetical expression at its middle: With fortitude (or other cause). Theyve fought

I've listened to it a many times. "With fortitude they've fought" works. Fortitude, however, doesn't seem to be a cause, and other is vague, making me suspect you were looking for four more beats. I'd put with fortitude they've fought all together. You still need four beats. Somehow put them at the beginning, perhaps: through the din with fortitude they've fought. You can choose your own particular words, but in this manner.

You say: "That pen's are weak". The apostrophe makes pens a possessive. You don't need that.

Good luck with your work.

Gaer