FWIW, none of those 4 pass the terminate test. You get nothing if they die immediately. I'd play Kokusho over all of them personally.
The horse is definitely dead, but I just keep swinging that bat...
I guess I just don't understand why 6 drops are required to be more than a 5/5 flyer with upside. I know many have been printed and will continue to be printed. If you just look at this from a power perspective, I get the position people are taking. I just don't see why super finishers make the game better. Assuming you didn't completely sit around doing nothing for the first 5 turns, if you got to this point in the game as the control player you should have stabilized already especially against an aggressive deck that blew their wad on Hellrider. You probably wrathed. You probably drew some cards and filtered to some answers. You probably got some two for one action going so you are ahead on cards (card quality if nothing else). Assuming you aren't at 2 life, at this point drop your finisher and win. And pretty much anything will do honestly. Now, if you are staring down a huge board position against you because your opponent's deck is better than yours or you just have a shit tuned control deck, I fail to see why your finisher (one fucking card) should fix that problem for you in one fail swoop just because you suddenly have 6 mana.
I don't want to go around in circles on this (and I'm repeating myself so the value add in this post is already questionable I apologize). But the way I see it, if you have super oppressive finishers that do multiple things (stabilize, play offense and defense simultaneously, etc), all you are accomplishing is moving the game to a more polarized state. By that I mean, you suddenly REQUIRE your aggressive decks to win the game before turn 5/6 or they essentially auto lose the game. Why is this a desirable thing? As far as I'm concerned, the more homogenized I can make the whole stupid ass aggro - midrange - control "theater" nonsense the better.
I will freely admit that this is somewhat a thought product of playing multiplayer and of having a group that gravitates towards midrange. So I'm coming at this from what is likely an atypical perspective.