The ter’angreal, the gizmos of the Power, have some very interesting and useful functions. The blunt dagger ter’angreal found in the Ebou Dar cache is a good case in point.
It is a small dagger with gold wire wrapped around a hilt of rough deerhorn, and a wide, unsharpened blade. Aviendha says of it:
"I think that if you have this in your possession, the Shadow cannot see you. Not the Eyeless or the Shadowtwisted, maybe not even Leafblighter…This knife makes a kind of warding.She thinks that if you have the ter’angreal in your possession, the Shadow, including Shadowspawn and possibly even the Dark One, cannot see you due to the warding it makes. No channelling is required.
- Knife of Dreams, A Different Skill
It struck me that the best use for this ter'angreal would be for Rand to carry to Shayol Ghul when he goes to confront the Dark One. Essential even. If Aviendha is right, and the warding is as strong as she thinks, the Dark One won't sense Rand's approach. The advantage with the dagger is that Rand doesn't have to channel or fiddle around with masking his ability and preparing inverted weaves and the like. Instead, he can concentrate on his target and what he has to do.
True, when Lews Therin went to the Pit of Doom in the Age of Legends he got in, sealed the Bore and got out again alive, albeit at considerable cost, but Lews Therin and the Companions caught the Shadow by surprise. The Shadow won’t let that happen again.
This ter'angreal alone would explain the Aiel Dreamwalkers' dream that with the Bowl of Winds is a treasure perhaps as great as the Bowl (Lord of Chaos, Matters of Toh). Yet from among the items found with the Bowl, Aviendha has also identified a white bowl ter’angreal that enables someone to look at things far away, and several ter’angreal (jewellery and figurines) which are long distance communications devices (Knife of Dreams, A Different Skill) all of which would be useful for organising and coordinating the Last Battle. No wonder the Dreamwalkers were keen that those allied to the Light find the Bowl, and the treasure, the cache, with it.
As for the blunt dagger, Aviendha thinks only of protecting Elayne from the Shadow, but it is Rand who will need it more than anyone, since he is going to Shayol Ghul itself. It is because Rand's lovers and friends don’t want certain events to happen that they have blinded themselves to what they could and should be doing – planning how to maximise his chances of success. Rand should take the dagger with him to hide from the Shadow.