Moenbryda

[Enkidoh]

But you did use it. The problem was

the fact your Blessing of Light was sealed by Midgardsormr earlier (at the end of Keeper of the Lake) and thus you could not draw from the Crystals to summon the Blade of Light at will to deliver the final coup di grace to Nabrieles. Hence Moen sacrificed herself by using her own lifeforce (that is, her own body's aether) to power it instead. The device actually did it's job, the problem was gaining the enormous amount of aether to power it. Realizing the auracite was not going to hold the Ascian for long, desperate times called for desperate measures, and she could see no other source of aether other than her own life, which she willingly did.

But as DJMau said, keep playing, it will all become apparent soon enough -

sadly it will not be the last time you see Scions sacrifice themselves like that either

.

[dragonseth07]

snip

I appreciate the input, but unless I'm mistaken, we used the tablet, not her device. Her device was laying on the ground the whole time. There's even a shot of it next to her.

[Berethos]

There's even a shot of it next to her.

Aerish mostly has the right of it - the device she created is meant to function somewhat similarly to how Tupsimati does. Tupsimati, however, is by far the more powerful so that's why the WoL uses it.

As for the device itself - I went back a couple scenes before to when you're testing it on corrupt crystals, and while she does note that it was successful in drawing aether, it was only a small amount ("Enough to make it interesting") and she was ready to refine it further with the intent that it would hold enough aether for the needs of the Scions.

In other words, it wasn't fully charged at all and was thus not used at all - likely it didn't hold near enough aether to be of any kind of help.