Card which the community is most polarized about?

Greetings, fellow LoR Card Discussion forum-browsers!

In the future, this forum will be mostly populated by threads about specific cards as they're announced.  Since we don't have that yet, though, I'd like to propose: which individual card do YOU think the LoR community is most polarized about--i.e., some many vigorously argue its too powerful while many also argue its perfectly balanced and/or undertuned?

I will submit Shadow Assassin.  I know there are flashier candidates, but those all tend to be tent-poles that you build your deck around.  Riot previously said this card was the most played card in the game, and I believe it--she is probably the single most independently-valuable card in the game.   However, every region should have "good" cards, and there will also be a best "good" card.  E.g., think of Omen Hawk, who has enough value to earn a spot in most Frejlord decks and yet we'd be pressed to argue he is too powerful.  The question is: is Assassin too good or is she just-right good?  I've seen convincing arguments on both sides.

EDIT: doh!  I started this thread because it was empty at the time, but by the time I finished, Arthas had already started auto-posting.  :-P

I know is beyond the scope of the thread, but how is Shadow Assassin balanced in any way?

Just think Shadow Assassin in this way: 
It has elusive, so outside of challenger units, try a wild guess wich is the best spell card that can remove her paying the least amount of mana?
Answer: Mystic Shot. 2 mana cost. So she is pretty much a 1 mana draw engine that also deals 2 damage, can block other elusives and do consistent damage if your oponnent doesn't have elusives/challenger units. This isn't balanced at all for 3 mana. I am surprised this card survived without a nerf to this day tbh. 

Back to topic... my horse is on Glimpse Beyond... but the card i hate the most is: Relentless Pursuit.

Quote From sinti

Dont even get me started on Omen Hawk, whenever i see it played against me on T1 i just want to concede. I hate that card with a passion.

Don't love it when Omen Hawk gets bounced by [Hearthstone Card (Navori Conspirator) Not Found] and replayed.  Then [Hearthstone Card (Kinkou Wayfinder) Not Found] finds the other two Omen Hawks and they drop a 7/6 Zed and a 6/6 [Hearthstone Card (Kinkou Lifeblade) Not Found]

-----------

Balance-wise: I agree with Helicopter [Hearthstone Card (Glimpse Beyond) Not Found] is pretty busted if played in response. No matter the outcome.  All you do is wait for the opponent to play removal. If you have no way to save it. Drop the Glimpse. You either get 2 free removals spells. Or 1 removal spell and 2 bonus cards.

Personal Hatred: [Hearthstone Card (Withering Wail) Not Found]. The Anti-Aggro card. I don't think it is unbalanced, it just annoying to play around. I hate playing aggro into Shadow Isles. So many stalling tools.