Mashies and niblicks and spoons, oh Da!

Got the answer. now get it again. I will bring this conflict to an end.

Winning every battle, never losing to an opponent, and being invincible. It may sound...

The world is spinning, round and round it goes. I think it's time for you to ...

I aim high but eventually come crashing down.

You may write on me, but never in my language.

I am a rectangle, yet I can create a vicious circle or a terrible spiral. (two words)

When you do not know what I am, then I am something. When you know what I am, then I ...

If this were my job title, you'd think I formed binding seals, not easy to break...