Aether sensing: Go ahead! Morgana's elemental affinity is wind, and he's strongly healing oriented. If you want to consider it an element or something, he's also very strongly aligned with hope. (As a magical creature, he's literally made out of hope; I leave it to you to figure out how that would shake out in Aether terms.) Power-wise, he's fairly strong--probably somewhere within the level 75-80 range these days.

The Echo: Feel free to do whatever you'd like with this; I'll feed you information as requested. He's got a bit of amnesia though, so I'm not sure if those memories would be accessible before they're recovered or not?