Regarding William Blake's Lamb/Tyger: What are powerful verbs used and what effect do they have on the poem?

To me, all of the powerful verbs are in "The Tyger." They are meant to show how fearsome the tiger is.

The verbs in "The Lamb" are really much more gentle -- verbs like "made" and "gave."  The most powerful verb there is "rejoice."  This makes sense because the lamb is gentle and the poem is supposed to be soothing and to represent the good in life.

By contrast, you have all sorts of powerful and scary verbs in the other poem.  You have "burning" and "dare" and "aspire" and "seize."  All of these are powerful verbs that show someone acting aggressively.