Not entirely sure why, but all bosses were a minimum of 7 levels higher than me throughout my shadowblade. Tore apart everyone right up until the woodling, which was level 20 to my level 12, barely managed to take him out, then went into lake of Nur, was challenging but nothing ridiculous. Got to sher'tul, and promptly got beaten into a pulp by an unstoppable weirdling. ah well, i'm used to getting pulped by roguelikes. off to try another character