User blog comment:SolarMist/Limit Breaking and Skill Levels/@comment-24388448-20141221055727/@comment-17760674-20141221184653

Let's say you have a lv.85 Artemis at skill 23.

You can use a duplicate Artemis to limit break Artemis to lv.90 (which will give you +1 skill because of the extra 5 levels) AND you'll get a skillup from Artemis being a duplicate. End skill level at lv.90: skill 25.

This can also work if your Artemis isn't at the skill limit for her level; HOWEVER, you'd pretty much be wasting the skill lv.25 opportunity if you fused a duplicate to her before lv.85.