A Flourish of Hate

My brother and I sat down and wrote a poem together. This is what we ended up with. Any thoughts?
What do you think we are referring to?

As I stepped out of the ruins,

I saw one of their kin;

A monster,

A murderer,

Who had, and will continue to, take many

Innocent lives.

He raised his arm, whose hand

Held a rifle,

But with a push and shove

I threw it aside

As my rage took over

And I went to the Beyond.

Rage aside,

I had only one task

Ahead of me.

As one last

Flourish of hate

Swept through me,

I picked up a rifle from a dead soldier

And shot him

Straight through his cold-blooded

Heart.

My task,

Now completed.