The Revealer LS is the one from Angel Wars that causes all opponents to reveal 2 cards from deck and put the revealed Lost Souls in play. I don't remember the verse reference offhand.
A unique character is any character that is not generic. Unique characters generally represent a specific person (or specific small group) from the Bible, be it Jacob or David or the specific Widow from Jesus' parable. For the purposes of Namaan's C&H you could play an enhancement if Naaman is using it but not if Syrian Archer is using it.