Wow, what a great ending for Miko. As much as we HATED her and were so greatly irritated by her, this bit shows that she really was 100% loyal to her beliefs right to the end, even willing to sacrifice herself to, in her mind, save the world from Xykon. True, it actually wasn't necessary as Soon had things well in hand, but Miko was still being truly heroic by destroying the gate.
What made it truly sad and touching was that when Soon tells her that no, she won't become a Paladin again, she doesn't argue...just quietly accepts the fact and asks about her horse. That was great.
Also, the fact that Miko was actually interacting with someone who she had the utmost respect for was refreshing and once again, made her character more than just the stubborn zealot she'd been in the past. Bravo.