CHALLENGE The_ CHAMPIONS LEAGUE, The_'s CHALLENGE CHAMPIONS LEAGUE

P.S. Please explain why Blindness doesn't work on skeletons with the black orb, but Berserk does...

Because immunities related to the "Immunity to Mind Magic" ability (which undead creatures have) are removed by the spell, but those related to the "Undead" ability itself are not (for example, immunity to curses is not removed). At the same time, immunity to blindness is granted by both the first and second abilities - and therefore, immunity to it is maintained with the spell due to the second ability. Trog lodites also retain immunity with the orb, by the way. But titans and elementals, whose immunity to blindness is granted only by immunity to mind magic, will have their immunity to blindness removed by the spell.