The stupid part is removing Shinten instead would have reduced a similar amount of APM and made your rotation MORE interesting overall, not less. The only weaponskill that loses to Kyuten is Hakaze, and that’s because there are very niche situations where you can justify spending the extra 5 Kenki to completely avoid overcap in your sequencing. You are generally rewarded for stockpiling Kenki for higher potency weaponskills, so Kaiten generally plays out more like Life Surge, but much, much more frequent, making it more intricate when there’s downtime and Third Eye interactions to account for.