Whenever this creature deals combat damage to a player, look at that player's hand and choose a card from it
Load up an opposing land with 3-4 copies of Psychic Venom, tap it with Icy repeatedly, and see how long the game lasts
His ability requires you to Firebend, Waterbend, Earthbend, and Airbend to trigger his transformation
With the correct setups and deck construction, this can often allow Glissa decks to return numerous artifacts from the graveyard in a single turn rather than the more restricted approach found in the aforementioned Emry
I think Mono Green decks may want to run it as a silver bullet, especially in playgroups that run lots of countermagic
If the card has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost