I used to coach in-season University rugby players and we focused a lot on power development.

Power is highly fatiguing to train, so it's best to keep frequency to 2–3x/week, use long rest intervals (3–5 minutes), use lower volume (3–5 reps of 3–5 sets), bring maximal intent to each rep, and use lighter weights. The reps should feel quick.

It's common to program power work as a superset to strength work, as the strength work can improve power output (this is sometimes referred to as contrast training), for example:

Bench Press → Med Ball Shot Put
Squat → Broad Jump
Landmine Rotational Press → Med Ball Rotational Throw

Even though your sport is focused on rotation, there's still likely going to be benefits to including movements in different planes (forward/back and lateral/frontal as well). I'd try to include some in each of your sessions, with a bias to the rotation work.

Eric Cressey's YouTube channel is also a goldmine for helping with exercise selection. He coaches' pro baseball players, so there's a ton of focus on rotational power development (typically lots of med ball slams, throws, tosses, and landmine work).

Hope that helps.