Simple Q&A D&D 4e Thread II: Electric Boogaloo

[tbergman92]

A479 - No, only the boost from the Siberys Shard of Merciless Cold could apply, for a few reasons. The most significant: You can only have one dragonshard affixed to a weapon at a time. Significant as to which shard applies: unless I'm missing the wording on Power of Storm, it only adds thunder damage, while the Eberron Shard of Lightning affects lightning damage. Also significant: Power of Storm and a Frost Weapon both change the damage type of your attack, so it wouldn't make the attack both Thunder (not lightning) and Frost, it would only be one on any given attack (You could switch the damage type on any attack by taking a free action to turn on or off the power of the Frost Weapon, but you would still only have one shard in your weapon, which you could only switch out during a short or extended rest).

Edited for clarity in directly responding to the question.