I never criticized Bon Bon. It's basically flawless.
Starcrushed had some real issues with animation quality, the scene with Marco and Jackie talking in the backyard is just the worst example. Some of the shots make them look like Family Guy characters.
The big action scene itself I felt was pretty underwhelming, the MHC barely puts up a fight, most of them get literally one-shot. Moon vs Toffee being mostly a magic sword duel was kind of weird. We seen Moon use her Butterfly form again for the first time since Game of Flags and at the time I was, again, a little underwhelmed by how it looked in this long action sequence compared to the big grand shot in that episode. Of course it's unrealistic to maintain that kind of animation quality in a dynamic action sequence, but a detail as simple as Moon actually Dipping Down (as she does in Tough Love) could have made it that much more intense.
I wasn't really comparing Tough Love's fight to the fights in any of the finale episodes, I was pointing out the great animation in that scene after the fight (which really stands out after how bad most of the rest of the episode looked), hoping that the finale can give us more scenes at that level of quality.
That said, the fight scene was pretty good for a standard episode. The visuals weren't spectacular and it wasn't exactly creative, but it was still pretty effective. Meteora overpowering Moon's magic and pinning her down while Moon gives this raw scream of agony, Moon brutalizing Meteora by just hurling boulders at her while Eclipsa looks absolutely shocked and horrified, and Eclipsa jumping in and Dipping Down to save her daughter were all good scenes. It all had "weight" to it and carried the personal/emotional conflicts between the three of them. I got a better sense of genuine hate and desire for revenge from Moon trying to kill Meteora than I did from her fight with Toffee.