sWord play

I build myself up,
Towering into the sky,
A knight entering battle,
For you to hear my war cry,

I run onto the field,
My message is my sword,
I swing towards my enemy,
Where I hope to strike a chord,

The blow is just glancing,
You see it off with a smile,
Then give me a lesson in torture,
In return for my guile,

It seems I forgot armour,
To protect me from my opposer,
If I am to be your enemy,
I have to get in closer,

So for now I am defeated,
When I was so sure of a win,
Another saying comes to mind,
Something about height and chin.