why are the others so inactive and what could be bran and arya's role?

[Bannerman of Winterfell]

the others have appeared in the first book and till now they have proven themselves to be very inactive. If they truly are so invincible why don't they try to bypass the wall via the shivering sea?

they have endless masses of zombies and from dance of dragons we see that they can swin,

dead things in the water. Why are they only coming out in raids and skirmishes, instead of all out force upon the wildings?

The wildlings have no means to kill them and now that they have no army, the white walkers can easily destroy them.

But if the wall truly is the ultimate defence against the walkers then why does the world and melisandre need azor azhai? They can beat back the others at the wall with ease.

The horn of joramun is destroyed in the eyes of the world but i think it is a fake.

From what i see, blood raven might use bran to break the wall somehow perhaps out of hate for the society that had wronged him? or is he a puppet of the Great other? or will he help to guide jon and stannis to victory with his omniscient abilities?

The house of black and white are probably in league with the iron bank of bravos and they will use assassins to cripple the iron throne's leadership. Will arya be the assassin?

But beyond the iron bank's favor and payment could the house have a greater aim?

they practice necromancy and other dark arts.

Isn't it highly probable that they are minions of the great other? Working to bring their religion of death into the world.

A faceless man is much more than a common assassin working for gold. Despite their fees i don't think money is what they want. If a faceless man wanted money, all he had to do was imitate businessmen and lords and run away with their gold or kill one and take his face and his life.

But they leave meager lives and have greater plans

[Señor de la Tormenta]

How can the IB be in league with the great other if they chose to support the only king who knows about this menace, and speaks openly of the need to fight against it?

Also, they lend money and ships to the NW to buy food for their men....

FL men...could be. But I really cant see the Bank working in this big braavos plot.

[sanzor]

Could it be that the Horn of Joramun is the Dragon horn of Euron?

[The Dornishman's Widow]

Could it be that the Horn of Joramun is the Dragon horn of Euron?

That is covered with Valyrian glyphs, while Joramun was a FM and so his horn would more likely contain First Men runes. So while it's possible, I rather think they are distinct artefacts. However, the horn of Joramun might be the old horn that Jon found beyond the wall and Sam has taken to Oldtown.

[Ahura Mazda]

IMHO white walkers can pass through the gate at Castle Black because it is not magical, differently from the gate used by Sam and the rest of the Wall..

These inactive people have gained thousands of Wights in the meanwhile, so it has been worthy waiting for the season in which their power is at its peak.. at the very least they seem to endure cold better than humans.

That is covered with Valyrian glyphs, while Joramun was a FM and so his horn would more likely contain First Men runes. So while it's possible, I rather think they are distinct artefacts. However, the horn of Joramun might be the old horn that Jon found beyond the wall and Sam has taken to Oldtown.

certainly, it is also true that we don't know what exactly makes that horn of Joramun so special, and it may well be that just like all effective weapons against ww are fire/dragon related it's particularity was to be a dragon's horn.. hence any other dragon horn may fit the role.