Can you make something scale to a skill level, rather than a particular stat? The steampunk classes from RotDG seem to work this way, but I'm not entirely certain. I had an(I think) interesting idea for a new skillset, but I'd like to know if this aspect of it is possible before going to the trouble of trying to code it.
The steampunk knight's stuff doesn't scale to a skill. It scales to a stat (tinkering) which is mainly boosted by the tinkering skill (aside from some other skills that boost the tinkering stat).