Well, initially I expected you'd use the dragonshard, until realizing it only technically works on weapons, which is a dumb notion. I honestly think it ought to work on implements just as well. I then figured Amnon would use the Bracelet, since it 1) is melee-oriented, and 2) features his deity's symbol. But one can never quite tell how their players will act.
Actually, now that I think about it, Cal
can make use of the dragonshard. Or rather, he will be able to, once he's got a magical version of his staff. Staves double as both staff implement and quarterstaff, so technically it applies in both circumstances. The wording of the dragonshards' properties don't say that they only apply to weapon attacks, only the damage of the weapon. I'm going to rule that in this particular circumstance, it would allow Cal to make use of the dragonshard, should Amnon relinquish it at some point.