Also I think we may be on the right track here:
What if electrope ISN'T native to Sphene's Shard but introduced via Ascian shenanigans as a surviving relict of the Rejoined Shard destroyed in the Calamity of Lightning? Like using the auracite and Thirteenth survivors in plots to destabilize the Source and the First, the elemental affinity is a red herring, and the lightning aether influence went wildly out of hand because of time progression and Ascian distraction.