I just gave Fae QR3 from QR2, and my arena score didn’t change! Help...

The score that you get, i.e. the opponents that you find are randomized and the score is based on your average arena weight of your team, which means that one match, you can find a 740 opponent and the other match, you'll get 730. This is caused by different arena weights in your team, which are setting your low and high points.

QR3 when compared to QR2 gives your Fae 2 more points towards her arena weight. If you also were to give her a 240SP C-sklil and a simple dual rally, you could raise her score potential by 6 more points to a total of 742.

Use this to see your scoring potential:

https://www.arcticsilverfox.com/score_calc/

Because how arena picks your score sucks; Your scoring potential is based on the average weight of your team and therefore is on a range of values ranging fro your lowest scoring member to your highest scoring member.

Yeah, I've been wondering about this myself. Noticed my Karla had a rating of 191 (shown when you sort units by rating instead of level or whatever) that didn't change at all when I upgraded her special from noontime to aether. What gives, IS?!

The most important factor in Arena scoring is merge level, BST (Base Stat Total) is about an 8th of that, and Skills are measured by their cost, but usually don't matter much more than 4 points per character, so you won't see any difference from improving just a single skill. For example, Legendary Marth and Zelgius score almost entirely the same, but Marth gets 6 less points from just the BST difference.