Never found one…. U craft them?
Yeah! I’ve crafted one so far
Mostly though, I get them from the world bosses. Have the seasonal power in the right spot, don’t die, and he’ll drop a page and 1/2 of NMD keys at times. Fills up your inventory and then some!
When you’re full.. make sure to drop the ones you have to make room for the ones that are on the ground. If you look at them and then drop them they won’t disappear. If you simply go to town and come back without doing this.. the ones you left will poof