If either the opponent or the permanent you control becomes an illegal target by the time Iroh's second ability resolves, the ability does nothing and you cannot choose to have the opponent gain control of the permanent
Like most Magic: The Gathering cards, the value of Voice of the Blessed depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Magic Online Promos)
Even these high prices, however, are nothing compared to the serialized Golden Chocobo cards
Not in a good way, mind you - one such Magic: The Gathering card saw a 90% decrease in price after the launch
If you happen to pay ten or more mana into Finale of Devastation, you get to give all creatures you control +X/+X for the turn, while also giving them haste, letting you attack with whatever creature you just tutored for
Whenever you cast a colorless spell, exile up to one target permanent thats one or more colors
