Invocation Clarification

I asked Eric this in a message on BGG, and thought it would help to post it here as well.

Swordwitches: I draw one Invocation to begin with, then play it. I do NOT draw another Invocation until I choose to discard the one in play, correct?

Right - You draw a single random swordwitch invocation for your witch. You can activate whenever you want (except as noted on the specific invocation - there's a few instances I think where you can't activate a couple of them), and it STAYS active FOREVER (even after you've quit the game and gone home), unless you decide to drop the power. At which point, you discard and are free to draw/activate a new invocation as per the rules on the SW card.

Think of it as a randomly accrued buff that stays in use until you get sick of it.