Maddening Hex deals damage to that player equal to the result
All that being said, this is a good red creature, but its far from my first pick for a prowess deck since it can be a bit slow, and the benefits arent all that great
beside having average Willpower for his class (4), Kohaku's is the only Mystic who combines high Intellect with decent Combat capabilities (most dump either one or another), having them at 4 and 3, respectively, though he wouldn't be particularly strong fighter unless he somehow boosts his Combat further or get his hands on good weaponry beside spells
The second effect lets you send an Elemental HERO monster from your Deck to your Graveyard and copy the Attribute and ATK/DEF of the monster you sent to the Graveyard
When it's the computer's turn in a duel, and it has to make a decision, it's painfully, terribly slow