[quote=@Apollosarcher]
[@Prince of Seraphs] I thinking a few more practical items, like the Double clawshot or horse call from Twilight Princess. 

Maybe the Roc's feather from Awakening and the oracle game, attached to the Pegasus boots.

Things the Heroes would want to give to another hero to help them.
[/quote]

Functionally I guess but I don't really think those are the kinds of things that would really be tied to another hero very strongly. It would be like having the item be the hedge clippers that the Hero of Winds grandmother got him to use a couple of times to tidy up the bushes. I think if the item is going to create a mental link across dimensions it has to be something that the hero who possessed it had strong feelings about, not just a tool he used. Like Skyward Sword Link's Sailcloth was a gift from Zelda, something he'd treasure. Or the telescope that was a gift from Aryll to Wind Waker Link.

Plus and this is really your call but this mental link between all of the Heroes would take some serious foresight and planning. The kind the Heroes never have time to do. One would have to assume that this was the plan of the Goddesses in which case all the Links wouldn't be sitting around debating which items they'd like to represent them cause they thought they'd be useful. If the item has the power to connect our Hero of Memory to another Hero across time and space and fractured timelines then it should be something linked very strongly to that person, not just something he used for awhile and then stored in his inventory never to be seen again.

Of course I'd imagine that some of the Links would have been strongly connected to this weapon or that but I don't think we should choose these items based on what would be the most useful. They're granting us the knowledge, wisdom and fighting abilities of one of the Heroes of Legend. They don't need to have there own powers as well.

Also pictures of Ghirahim and Fi:
[hider=Ghirahim]
[img]http://vignette3.wikia.nocookie.net/zelda/images/d/d7/Ghirahim_Artwork.png/revision/latest?cb=20110608165337[/img][/hider]
[hider=Fi][img]http://vignette4.wikia.nocookie.net/zelda/images/3/34/Fi_Artwork.png/revision/latest?cb=20120329024228[/img][/hider]