Here's an example of a verse that leads up to the last line and makes it more powerful. From Kipling, the Last Rhyme of Thomas the Rhymer:
"Sleep ye or wake," True Thomas said,
"That sit so still, that muse so long;
Sleep ye or wake? -- till the latter sleep
I trow ye'll not forget my song.
"I ha' harpit a shadow out o' the sun
To stand before your face and cry;
I ha' armed the earth beneath your heel,
And over your head I ha' dusked the sky.
"I ha' harpit ye up to the throne o' God,
I ha' harpit your midmost soul in three;
I ha' harpit ye down to the Hinges o' Hell,
And -- ye -- would -- make -- a Knight o' me!"
That's a last line.