I really like this idea, because (like the new card Seraph) it duos with fire but this time adds some actual value to the Light-side of the deck.
I like the unupped version, 4/6, because it has an obvious synergy with Rage Potion. However in that respect the upped version disappoints because of its lower defence. I might suggest, upped costs 6
, and is 5/7 or maybe even 6/7 - I haven't thought about the attack much =p
*Edit* I see that you also get
for when it takes damage in the upped version too. I still think it oughta have 6/7 defence tho, so if that's OP maybe leave the ability as unupped? Just thoughts...