How do you compare two trends on the same chart when one metric higher = positive, second metric higher = negative?

So we have two metrics that could potentially go on the same chart because they are semi-related and the user will want to compare them. However, when the first metric has a higher percentage, it is positive. If the second metric has a higher percentage it is negative.

We were originally going to use separate line charts, but I am leaning more towards combining them into one chart. My only concern is that having these both as a line graph on the same chart might be misleading or confusing for the user to tell if the trend is positive or negative overall.

Have you seen or created a chart with a similar scenario to this?