I completely agree with you that the interval you chose functions exactly the way you describe. What I find especially interesting about it is that the interval is a major third, and while you skip the minor third in the walk up between these notes, the implication is heavily minor-sounding that fits a villain theme well. I also think that your intuition of putting the melody in the bass voice while keeping other parts more sparse fits the vibe of this jam theme really well. Thank you for sharing!