Hey, thanks for playing! There won't be any other playable characters but, in the full version of the game, there are about 20 different unlockable artifacts in the game that gives the player different powers/powerful cards. Full release is close. I'm just ironing out some of the last known bugs and adding missing sound effects at this point. Blood mana is used for re-rolling card choices when you are building your deck. Each other mage you beat gives you increasing amount of blood mana depending on the level.