Just Bran.
I never thought the Direwolves as magical. Just rare and not domesticated.
I could be wrong, but I don’t recall anyone but Bran and Wildlings being able to warg.
If so, only Bran’s and Jon’s have encountered Walkers to date. Bran’s, like Hodor, died buying time so he an Meera could escape from the Cave of the Three-eyed Raven.
Now that I think about it, Summer would be a good candidate for coming back as a Dire Wight. He’s the only direwolf that died north of the Wall.
Bran’s old friend?
There is definitely something magical about the Direwolves. Bran woke up from his coma the instant Lady was killed, indicating a connection between them. His direwolf appeared out of nowhere to save him from the assassin. Ghost also began howling far away when Jon was stabbed.
I was certain Jon had been having dreams where he was seeing out of Ghost’s eyes, but now I’m thinking that might have been in the books. But there’s no doubt that the direwolves in the show have a pretty much mystical ability to be in the right place at the right time, to understand who is bad and who is good, etc. Jon’s direwolf appeared out of nowhere to save Sam when he was protecting Gilly, for example. You can call it Canis ex-machina, I guess, but GRRM isn’t that trite of a writer, and these events were also in the book. I think the direwolves appeared after 200 years as protectors of the Stark Children because the Stark Children were important to the future of Westeros.
There was also great symbolism in how the pups arrived. A direwolf (sigil of House Stark) and a stag (sigil of House Baratheon), killed each other, but in so doing helped the pups land in the hands of the Stark children to help them rise up. In a way, that’s exactly what happened. Ned Stark and Robert Baratheon were locked on a mutually self-destructive path, putting the Stark kids through a trial of fire that actually hardened them and made them the people they needed to be to fight the walkers.
Please see the OP, and don’t refer to the books here. Thanks!
Predators don’t usually eat other predators for a reason: they’re too rare to make it worthwhile to hunt them. The dragons would have to expend more energy looking for bears and wolves than they would gain by eating them.
If that’s their job, they haven’t exactly been Lassie, Rin Tin Tin, or even Snowy. All together, they’ve only managed to successfully protect Jon and Bran, and the latter only by self-sacrifice. So far the count is 2/6 dead Stark children, and 5/6 direwolves dead or AWOL.
Not getting the point. One of the dragons is also dead and working for the other side.
I see it as the forces that drive this cycle bringing a number of players into the game. Bran, for example. Melisandre. The dragons. The direwolves. In this story’s lore I don’t think it’s a coincidence that a Targaryan would be raised in Winterfell just as the white walkers return, and that another Targaryan would arrive in Westeros with three dragons and an army and ally with the one in Winterfell.
I also think Arya’s adventure/ordeal was probably pre-ordained as well, to give her the tools for the fight to come. I think she was allowed to leave the house of black and white alive, after a final test to make sure she was worthy, so that she would go off and help fight the common enemy. What happens to her afterwards is another question.
But this is just my fan theory. I can’t claim to be able to provide all kinds of evidence for it, other than that it seems like all the pieces are conveniently falling into place. Maybe fate is stronger in this universe or something. I also note that all the Valyrian Steel blades in the kingdom except maybe one or two are now also where they need to be, even though no one really planned that. Sam has his family’s sword, seemingly grabbed on a whim. Arya wound up with a Valryian steel dagger. Ned’s greatsword was melted down, and I think the two swords made of it are both in the north now, aren’t they?
Also, we know that King’s blood is powerful magic, and we now have Gendry, John Snow and Daeneris in the right place. And soon Theon, I guess, since his dad was the king of the Iron Born and he was heir to the throne.
It feels more like shadowy forces putting all the pieces on the board in the right place rather than dumb luck or coincidence. And the direwolves are part of that. My theory, anyway.
But the people they saved are utterly critical to the battle to come. Of the others, one was forced away by Arya and remains in the north and will probably wind up fighting, even if we don’t see it. One was killed on orders from Cersei. One is still around protecting Jon Snow and whoever else needs protecting. Robb Stark’s was killed, but then Robb was also dead, so that direwolf kind of lost its reason to exist. The same with Shaggydog. The only people still alive with a dead direwolf are Sansa and Bran, and Bran’s gave his life to help get him to Winterfell.
Also, just because the direwolves are part of the battle between the dead and living doesn’t mean they are going to be 100% effective - or even effective at all, necessarily. Just as the battle to come could be won or lost.
Brienne has one and she’s there, and I think Jaime has the other and he just arrived. Do I have that right? Joffrey’s sword went to Jaime after Joffrey was killed?
Surely Jorah will wind up with something. Probably Sam’s.
Summer saved both Bran and Cat by killing Bran’s would-be assassin. Nymeria saved Arya from almost surely being gutted by Joffrey. And if you want to count Bran’s warging, Summer and Shaggydog saved Jon, Bran, Rickon, Meera, Jojen and Hodor. In fact, it’s possible he only wargs into Summer, meaning Shaggydog attacks the wildlings on his own just by following Summer, because it isn’t totally clear if Bran is controlling both direwolves. He might be, though.
That being said, they haven’t exactly been as directly important in the grand scheme of things as so many of us, I think, inferred from their introduction.
Just that if I had a supernatural giant wolf protector I would want it to be at least as effective as Snowy. 
Dany’s dragons have played far more of a role in keeping her safe than any of the direwolves. But I was joking a bit.
Heartsbane, of House Tarly, was stolen and brought to Winterfell by Sam.
Longclaw, of House Mormont, was given to Jon Snow by Jeor Mormont. (If he hadn’t become an outlaw, it would have gone to his son Jorah.)
Ice, of House Stark, was melted down and used to make two swords. Oathkeeper was given to Jaime, who passed it on to Brienne. Widow’s Wail was originally given to Joffrey but is now in the possession of Jaime.
Littlefinger’s Valyrian steel dagger (unnamed) is now in the possession of Arya, but she mostly uses Needle, an ordinary steel rapier given to her by Jon Snow.
I believe those are all the Valyrian steel weapons known on the TV show, and all are in the possession of characters now at Winterfell. Except for Sam, they are all pretty potent warriors.
The finale was just leaked. It is a very red ending.
#RespectIsComing
Although Sam is only one of two to kill a White Walker.
Good point. However, he killed it by stabbing it in the back with a dragonglass dagger. I wonder if he’d even be able to swing a longsword effectively.
Is this a joke or is it a real spoiler leak? I’m not clicking on it without being sure.
According to the OP:
Is this information about an unaired episode or not?
It’s safe. And moderately funny.
Okay, that was fun.
I don’t. Prophecies are often vague, inaccurate and/or confusing.
That was hysterical!
Ghost found the dragonglass weapons on the Fist of the First Men. Sam ended up with one, and it was at hand when he needed to stop a White Walker. That’s how they found out that dragonglass kills them.
Without Ghost the story ends here. There are also many who believe that Jon warged into Ghost when he was stabbed, and otherwise would not have come back to life. So without Ghost the story may have ended even sooner.
Bwa hahahaaaa!