Is Dragon Ball Z episode 159 filler?
Canon No, episode 159 of Dragon Ball Z is canon.
#159
The Last Defense
全宇宙に衝撃！！セル、完全体へ驚異の進化
Aired 30 Sept 1992
Canon No, episode 159 of Dragon Ball Z is canon.
#159
The Last Defense
全宇宙に衝撃！！セル、完全体へ驚異の進化
Aired 30 Sept 1992