When Elenor gives you the mag cell, what happens if you make the mag grow? Do you keep the mag? Is there a new ending? PLEASE TELL ME!!

Elenor takes it back, I presume.
But, why would they have the mag "move" periodically? I can make the mag "grow" twice. It's a jip if that's all that happens. I guess you're right though. Montague says that the mag cell can get hurt from other mags and it's dangerous.
There is a way to get an extended ending scene on that quest after making the mag grow a certain amount of times, but it involves a complicated series of quests and sidequests beforehand. It's TRULY worth the work, however!
So, do you know how or have you heard that from someone else?
I do know how to do it, and have done it myself. Its really great! Someone from here told me how to do it, so if you want you can PM me and I'll send you what he sent me!
That'd be great!

What is the ending though?