The reverse lunge with a twist works your legs and obliques.
Reverse lunge with a twist form cue:
Hold a medicine ball or dumbbell and stand with your legs hip width apart. Take a big step back to come into a lunge position. Watch your alignment and make sure your front knee is stacked over your front ankle, and your chest is lifted with a tight core. Twist your body towards the front knee, then straighten back out and step the back leg in to start position. Repeat to the other side.
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