is jujutsu kaisen episode 28 filler?

Toji kills Riko moments before the merger. He then fights Gojo and wins — stabbing the strongest student through the throat with a weapon that bypasses Infinity through sheer physical speed.

Gojo dies. Then, in the space between death and oblivion, he figures out reverse cursed technique, heals his fatal wound, and unlocks Red.

Combining Blue and Red, Gojo fires Purple for the first time and kills Toji. The strongest sorcerer in history is born from the worst day of his life.